I highly recommend this mod which will allow you to refine or remove the romance feature to your liking. I largely agree with what you wrote, though it could have done without the insults, lol. Romance should be initiated by the player to avoid unwanted advances, and it generally has more depth when the companions have personal preferences. I'm okay with playsexuality overall, but I only prefer it if there isn't a large enough roster of romance options (DA2, for example). BG3 has 8 romances in total, so they could have added diversity of preferences while still giving everyone a good variety of choices.

That being said, even if the companions had designated orientations, the overall romance experience would still be flat and a bit of a letdown. Resources and time were spent in less important parts of the game (IMO, origin characters, giving dialogue to unimportant NPCs, etc.), and now we have a subpar main story and somewhat lifeless and often unreactive companions.