@Ethreix I think you might be attributing too much of a game's success exclusively to its combat system, and also falling victim to confirmation bias.

In your first post it is made abundantly clear that you don't like the D&D/BG3 combat system, but you list a number of problems with the system that are entirely subjective while treating them as facts, and then you make wild assumptions like how DOS2 fans will be very disappointed with BG3 because it uses a D&D based combat. BG3 has arguably more things in common with games like DOS2 and DA:O than with Icewind Dale and probably even the original BG titles, even in terms of combat, while BG3 and BG1&2 are both DnD, they play very differently, but you're reducing it all to just DnD vs NotDnD combat.

You're taking way too many things for granted for this whole "research" to have any actual validity.

Also, just by looking at those numbers you posted, it's almost safe to predict that BG3's only real competitor to beat in there is DOS2, the other Larian game, maybe the difference doesn't lie in what specific ruleset is used but in how the game is approached as a whole.

While I disagree with wild claims like the one Volourn made, I believe that a DnD based combat system CAN be very successful if done correctly, but still, reducing a game's success to just one of its parts doesn't make much sense, if BG3 ends up being as successful as it seems it will be, it won't be explained just because of what combat system it uses.