Precisely as you said that 5e is easier for new players. I've never played any DnD prior to playing BG3, but taking the time to really understand 5e its been pretty easy and fun. I have to history with 3.5e vs 5e but overall I think its been fun.
With the game doing all the calculations and rolling for you, 3.5e mechanics wouldn't be any more difficult for a player to grasp. It would mean you could do a lot more with feats, have levels over 20, upgrade weapons, armor, and other wearable items, and really customize your character - but if you opted not to do it, you wouldn't even notice that added complexity. 5e is easier to grasp, but it also is extremely restrictive on character customization and really stereotypes characters. For example, evil and neutral clerics used to be able to rebuke undead instead of turning them - that put the undead under your control. If you worked with skills instead of proficiencies - which was really useful for intelligent characters who got more skills per level - you could easily make your wizard able to sneak around and after enough levels you could turn them into a steath spellcaster that could cast silently, without movement. If you wanted to make a rogue skilled with dealing with arcana or religion you could do that without sacrificing their acrobatics. Or you could play it vanilla. The complexity had to do with the paper, and you would notice no difference in gameplay. In fact, you would have a lot more cantrips as you had a huge list of level 0 spells.
Obviously Wizards is going to insist that any games currently being made are going to use the current rules in order to promote their brand.
But I’ve been playing DND since the 90s and I think 3/3.5 was trash, and so do all the people I play with (also long time table top vets). If you like those rule sets that’s cool, but 5E doesn’t just appeal to new players. Lots of older players appreciate that the game is significantly decluttered and less convoluted now.
The people I play with agree, at least the adults, that 5e is trash - just too simplified, though one wanted to play a race that was only available in 5e. But one (a juris doctorate) hadn't played since the 90s and the other (a PhD) hadn't played before and they need to be reminded of the rules when we play. Playing within the confines of a video game, though, no one has to keep track of the rules. 1e players tend to like 5e as a return to the basics, and players do focus much more on storytelling than rolling and keeping track of stats, but all those advantages disappear with the videogame format. Players don't have to keep track of stuff and the storytelling is the same regardless. All the changes would be behind the scenes other than in leveling up and character creation and those changes would only make characters more customizable. You wouldn't see the clutter in the game.