I would say that they are right, at least in a way.
They certainly know how to reach more players.
If you compare DoS2 sales to its competitors, it doesn't look too cheerful. Overall, DoS2 sold better than most of its direct competitors combined.
You can argue whether they were better or worse games than DoS, but it doesn't really matter.
If you look at it this way, Larian does know "what works".
It is not without reason that WoTC was chosen by Larian and not for example Obsidian, which had to be rescued by Microsoft after the last mishaps.
Speaking as someone who learned of DOS2 around release period, it had absolutely insane word of mouth. It was released during a period of time where turn-based was seen as a gameplay format that was dying out and a relic of the past with open hostility towards most games that had it, so tons of turn-based enthusiasts flocked to DOS2 and began to champion it as a revolutionary game in tactical thought. Which, it pretty much was at the time, for field effects and so on were a really novel idea. The multiplayer helped a lot too, which was another huge factor - and no other modern cRPG that I am even aware of has had it due to the massive budget and coding framework needed to support such a thing.
It was kind of a phenomenon, one that any other cRPG would be extremely lucky to have that kind of attention.
BG3 now is benefiting from Larian's 'brand' and the DnD branding at the same time. Look at how much attention the gaming press is giving this game, while they won't give any other cRPG developer the time of day nowadays. Admittedly among the more hardcore cRPG enthusiast sites that I've been observing, there is a bit of resentment over this, that while there's a lot of new cRPG fans, the majority are only fans of Larian games rather than cRPGs as a whole. Otherwise, projects from even a celebrated developer like Obsidian's Pillars of Eternity 2 wouldn't have completely died in the water, and most other cRPGs still wouldn't be struggling to get any kind of audience at all. Even Solasta isn't really taking off even though one can easily argue that it can stand up there with DOS2 and the XCOM games in tactical thinking, largely because the graphics and lack of multiplayer are big stains on it. Things that a low budget cRPG can't have, and cRPGs in general have been inherently lower budget for a while.
The only other cRPG to come close in attention lately are the Pathfinder games, and that's largely because we're now seeing an opposite effect of RTwP being seen as the archaic gameplay format that's in danger of dying out, because DOS2 changed everyone's perceptions so much. Kingmaker also turned out to be an unexpectedly good game in a year where people thought PoE2 would dominate, with a unique premise and more grounded writing than what Larian is famous for. So those enthusiasts are attempting to champion that series to simply keep that style of gameplay alive. As time goes on, DOS2's success is looking more like a flash in the pan or branding thing that's not benefiting the rest of the genre as a whole - if anything, it's potentially done more to benefit jRPGs that are starting to utilize similar ideas to what DOS2 had, like the recently announced Triangle Strategy.
That said, absolutely none of this means that BG3 should be free from criticism though. It's really an irrelevant side topic at the end of the day. If there are flaws that are this noticeable during EA, they're all going to be stressed by the final release if the systems in place remain the same as is. The most contentious topic that I've heard of that existed during DOS2 EA was the armor system, and even the flaws for that did not really become that disruptive to someone like me who came in after the EA period, until it became obvious that it was the primary reason for the massive stat bloat and bosses being designed with rocket tag tendencies towards the second half of the game.
The best one could hope for by final release is that the higher level features and spells somehow swing the mechanical balance of power back towards DnD (which it inherently should, yet it would also depend on the encounter design for the rest of the game as well). But with us unable to test level 5 as is and all communications pointing towards the devs keeping everyone in the dark on this front until final release, one can only guess.
All I can say is that I hope a bunch of people here don't end up with surprised Pikachu faces if height advantage/backstab advantage/shove mechanics end up remaining completely dominant throughout an entire playthrough of a 80+ hour cRPG, and majority opinion on the game's combat starts to sour after release for it because half of the other mechanics are seen as irrelevant in comparison (except for some super niche situations that will undoubtedly be brought up in an attempt to defend the combat design). DOS2 managed to avoid that kind of perception for the most part, because very few base skills in that game really had niche applications, the cheese was actually not very obvious in actual practice, and the cheese wasn't worth the time it took to set up (though a lot of the source skills could have been balanced a lot better, the issues with those were really more about the source cost being tied to them than anything else, especially in regards to Bless). This, when a bunch of people here that are sometimes outright demonized by a certain content creator and the BG3 subreddit have been trying to warn everyone of the long term concerns with those exact systems, for perhaps an entire year or longer beforehand.
