Avoiding the obvious comparison to Diablo, in terms of the combat BG was an action RTS game more than a cRPG in the tradition of the early MM games or SSI gold boxes. BG1 felt very much like a Warrior/Rogue friendly campaign, whereas BG2 leaned more heavily towards Priests/Wizards. In practical combat terms though, both BG1/2 felt more like Starcraft or Age of Empires, than say Pool of Radiance or FR:UA.
The BG games didn't have to rely as much on the nuts and bolts of D&D TB combat mechanics, which it instead used more like flavor to inform the action RTS vibe they already had going. It was basically an RTS game with D&D window dressing. I loved it, of course. Since 2003 most moves have been to make the D&D computer games feel more in line with the table top, which is cool, but also very different than what BG1 did. I honestly think they should have picked a different Name or another popular campaign to launch a fully turn based cRPG, so that Baldur's Gate could have remained a bridge between Dungeons and Dragons and other popular sorts of games.
BG was mocked a bit by table top players for being the game that was "all about launching fireballs just offscreen" or like casting command (BG1) or insect plague (BG2) and if it didn't land, you reloaded lol. BG2 was the king of Q for quicksave, and playing every fight 3 times until you understood the meta. Which is not really how PnP D&D works at all, but it was still hella fun.
It's a little too bad that the "with pause" genre has been pretty much ceded to game settings not in the Forgotten Realms or IPs that are no longer officially "D&D". BG3 could easily have been the game that perfected the RTS with pause style of gameplay, in a modern 3d environment.
I think what they did here would have been better suited for a NWN3 game, which always had a super shitty combat system as the main thing holding it back. It really would have benefited from a 1:1 turn based combat system straight out of the PHB. Neverwinter 3 would have had the same kind of name recognition that Baldur's Gate had, and would have fit much better with the co-op MP type thing that Larian is doing here.
It's just one of those face palm type things, where I keeping asking why they did it one way rather than another. I guess maybe they figured that a new Baldur's Gate had to come first in sequence, because of the way nostalgia windows work in marketing, but it feels like a bit of a miss for what they are actually doing. I think they kinda conflated the audience of Baldur's Gate games with the audience of Neverwinter. BG was the single player full party focused game, that merged fun action-y rts gameplay with the FR setting. Neverwinter was the game that was supposed to be MP oriented and focus on actually translating the table top experience into a digital format. I can easily picture what they are currently doing in BG3 or say Solasta, as following in the NWN tradition. If they hadn't made it instead into an mmo. Whereas with the BG style game, those no longer exist to connect to the main IP via a more RTS style. So I think they lose ground there, to say a Dragon Age or Pillars or Pathfinder. Like kinda burning a bridge into D&D, the one that put the setting before the rulebook, as a hook. If that makes sense?