Wait so what is your complaint though? The OP failed to provide any concrete issue.
Is it that BG3 is a D&D based game, turn based, with faithfully implemented D&D systems, unlike real time BG1 or BG2 that were at best "D&D themed" in how they handled cast orders, spells, cantrips, controls and everything else?
Or is it that BG3 while incomplete has an incredible story telling, characters, replayability with multiple solutions and paths through most zones/encounters seen so far?
Because those are all upsides, not downsides.
Is this game a BG1/BG2 clone, with absolutely no changes to control scheme and systems? No. But it's not based on D&D Second Edition like BG1/2 were. And if anything it is WAY more faithful to 5E than either of those games were.
Is it different? Sure! Very! But the spirit is there.
I think the reality is that with BG 1/2, Bioware was attempting to adapt 2e DnD to the PC, they just chose poorly with the RTwP due to James Ohlen's love of Warhammer, and the popularity of Diablo at the time, and had to abandon parts of 2e that wouldn't work in RTwP because they were too dependent on a turn-based environment.
Whereas Larian, has claimed to be adapting 5e to the PC with BG3, but really just took DOS mechanics and haphazardly slapped a few 5e concepts on top of them.