BG3 has done a better job than many games, and many games which receive a lot of plaudits for variety also don't get much better than this.
The main issue with the whole "leave it for the Mods to kill" concept is that then we are still at the mercy of a UI that was not designed to handle much more than say a 25 head cycling scheme.
We are also at the mercy of random amateur modelling artists and whatever their tastes might be. Then at the mercy of whoever does the eventual compiling and curating, and attempts to put all that stuff together in one place on Nexus. Usually with a name like "The Ultimate Head Mod" or "More Beautiful Faces Mod" etc.
A lot of times it will start small. So perhaps someone will say "Hey, why don't we have an Anya Taylor-Joy looking head yet in BG3?" so they make one of those (I would never complain there, she should definitely be an Elf! lol). And then someone else is like "No no! what we really need is the Zendaya head!" so if we're lucky we get that too. Then maybe it will have some faux It-Girls added into the mix like that. Maybe someone who's older says, "But what about the Angelina Jolie?" or even older "The Phoebe Cates or Elizabeth Shue?" or even younger "the Millie Bobbie Brown?" So you'll get a hodgepodge, with various different levels of artistry or celebrity mimicry, and in the end we might have a few more winners like that, but overall the spread remains limited and arbitrary.
This happens with the male heads as well, though typically with more differentiation there at the outset, because (just like in popular animation) they tend to start with more bases covered, and more tropes on offer. The male heads aren't exactly scrutinized in the same way. People aren't usually freaking out from the lack of Josh Brolin heads, or how all the Male heads are "too ugly" etc. It's just the sad commentary on how these things tend to work differently when it's all gender charged and down to Beauty vs "I want gruff Dwarves with even gruffer beards! And can we get more giant noses while you're at it?" lol. But still, you'll hit the same walls eventually, just with a different sort of emphasis there, for reasons that would take too long to cover in this thread.
The same lack of variety in the end though, when it's all left up to the arbitrary caprices of random Modders. Then on top of that, you get a further issue of content overload with mods, since users don't like to download a bunch of separate mods where one big mod might do the trick. So eventually you'll end up with a gigantic mod with a whole huge glut of available models put together in one spot. This might take several years to create, cause (big surprise) unpaid amateur enthusiasts won't be beholden to deadlines. By the time the work is complete, the game has likely already moved into the afterlife. They don't strike when the iron is hot, and again it becomes very unwieldy as you move from cycling between 30 heads to cycling between 300, and where the tastes of some random contributor to Nexus might be pretty different than your own tastes. This is why it is on the developers, not the modders, to provide us with the fundament and the scaffolding and the support.
People will frequently claim that this is luxury work, that there are more important things to a game. But I know with an absolute certainty, that for whatever RPG one might love the most, if it had a custom character creator, you probably spent more time playing with that than the actual game lol.
It's in fact so important, that the staying power and replay of a game often comes down to how well the character creator is executed. Skyrim was mentioned, that game had notoriously terrible heads/faces initially and still does on consoles and without mods, despite being re-released a bazillion times. SWTOR which is one of the most popular MMOs next to Warcraft, also creates huge a timesink on character creation and relies on it for consistent revenue, trying to bill it all in annoying microtransactions. But even if one spends the money and the time, it still tops out well under that 125 Per number I've suggested many times, and still shows a ton of similar morphology and many missing bases not covered.
D&D is supposed to be the game, more than any other, which leans into this concept of anything you can imagine. It's why the old classics provided custom portraiture (and no surprise again) mods that sought to produce "The Ultimate Portraits" pack were a dime a dozen. (Except for mine of course, which were always legendary! heheh But honestly, everyone has their own sense of taste there right?) This is why I'm trying to help Larian get the leg up here. Of course it is very simple to disguise what's happening beneath the surface by randomizing and recoloring and using mixed up defaults and misdirection. You can get a ton of mileage out of it, clearly. I mean just look at what we have here. We don't really have 100s of heads, as I'm sure many people might have presumed from their initial impression. We probably have something closer to 25 heads all told, and everything else is just a subtle morph - different makeup, change the haircut, switch some colors and presto! Right? But over time the player will come to see that they (the player) don't give equal weight to what's on offer.
Niara mentioned halfling head 3 with the larger eyes. Everyone has one head like that for each fantasy racial set probably - the one that just looks better to them and so they always choose that model and none of the others lol. They habitually gravitate towards the base options they prefer, and give the rest short shrift.
I know it will take me a while to do all the male heads in Profile 3/4, so I just wanted to reply real quick to gives some further thoughts on why modding is insufficient. Also to note that the artists and animators who are responsible for the modelling are almost certainly a different crew than the people doing the code and such, or mapping out the UI, so it's not exactly like one takes away from the other. They all buttress and support one another, but the modelling and UI works tends to be scrutinized more heavily because it is primary, the stuff we engage with first and foremost.
Particularly when a game is in the state that BG3 is in currently, a more robust character creator buys them time. Again, because the more options that are available to the player, the more time the player will sink into Character Creation and repeat playthroughs. It helps the circle to hold, while the other stuff is being worked out and offers engagement long after the point when the game has effectively been played to death and the player should probably move on. But put an Anya Taylor-Joy in there, with a few more haircuts and outfits and makeup designs, and watch players sink another 50 hours into it. That's why its so frustrating that they are obviously trying to save stuff for the full release, and why certain faces are walled off just for NPCs say. They probably think they can get away with 25 heads for now, and another 25 when it goes live later, but that's still only 50. We need 250! And we need an interface that can handle that sort of volume comfortably, so the player is engaged creatively instead of presented with a bunch of tedium or an unwieldy layout for the presentation.
ps. Here are the two views stacked for the female heads...