Larians are treated like that because they are the only developer who managed to make a CRPG and actually have it turn out good.
The only other ones i can think of are pathfinder kingmaker and shadowrun returns dragonfall.
And those werent nearly as much of a commercial success.

And im sorry waht simplifications. DnD is an incredible simple system. 2E was even more simplistic.
And no, THAC0 is not complex, people just got confused that lower numbers are better. BG didnt even have opportunity attacks and you are going to tell me modern RPGs are more casual than that?
Skyrim is maybe, but we arent talking about Skyrim here, we are talking about OS2, Pathfinder Kingmaker , PoE, Age of Decadence, Shadowrun and the like. Almost all of these games added new things without removing old things.

You people keep beeing salty about..... larian for some reason. Just admit it, you are a nostalgic Boomer and no matter who makes this, you will always be dissatisfied.
You will never be happy because you think it will tarnish your memory of an old game that realy wasnt as good as you think it was.

AS for WOTC: what they want is a good game. WOTC hasnt made a lot of DnD games and those that it made all failed. Thats because the companies they had at hand didnt know what to do, they all tried to recreate baldurs gate. I mean Beamdog is literaly a studio who did nothing but rework baldurs gate.
Turns out, living in the past does not work.
And if they would hire Obsidian to do it, and Obsidian would make Baldurs gate 3 in the infinity engine or their new engine thats basically the same, youd still hate it because its new.
And other people would hate it because its not innovative. Just like nobody liked siege of dragonspear.
Because nobody needs a Baldurs Gate addon today, especialy not such a lazy one that doenst improve the game at all.