Not sure I agree with your premise as some of the 5e feats are arguably overpowered and character defining, and in BG3 some of these have been made even more powerful. Thinking first and foremost about Great Weapon Master (-5 attack/+10 damage), which will be boosted A LOT by virtually guaranteed advantage on attack rolls. Sharpshooter will no doubt be implemented for ranged characters. Moderately Armored is another feat that might make a lot of sense as it boosts AC significantly. Then again, once multiclassing enters the equation, there will be less ASI/feats to go around...
Right now the balance is near broken by excessive homebrew, so this might be kind of a little premature?