@Marielle, thanks for posting the video! I watched it a few times, and I've got two takeaways.
1. Larian consider romance as a feature that strengthens the product.
Among the three reasons given as to why romances matter beyond fan service are "Romance will be the longest tail part of the fandom you create" and "some communities will feel automatically included in your fandom." Maybe it was just how the talk was structured, but Larian show here they have no reason to include a feature aside from fan service.
2. Nowhere is any kind of thematic relevance to the rest of the game even discussed.
The lack of focus on theme or connection between romance and the rest of the game speaks volumes on how BG3 was put together. The romance writers created their own work to maximize their own audience and plopped it into BG3, where thematic cohesion was never a consideration.
Trigger warnings for stuff in BG3
The inciting incident is sexual assault - at least metaphorically. It happens before the player defines anything about their Tav and is the one shared trait between all player characters. Whether or not Larian recognise it, sexual assault is at the thematic core of the BG3 experience.
Never addressing it directly doesn't help, the story will still be interpreted by some players through that thematic lense. When Halsin chides you for skipping content (perhaps because you were subconsciously in fight or flight mode) Larian are saying "survivors of sexual assault should really get over it and enjoy life." When Nettie and others suggest you kill yourself, players with the "sexual assault thematic lense" will read that as Larian saying "survivors of sexual assault should consider killing themselves".
That could be a message for a work of art - one I wouldn't get behind - but the case here is worse, because it doesn't seem to be intentional.
The writing team is particularly proud of an exchange with Astarion where choosing flirty/sexy dialogue options will get him to sleep with Tav once out of a sense of obligation before ending the relationship. All this because the player didn't read Astarion's hesitation between the lines. "This is all a game, to you!" he realizes the morning after.
Eff off, Larian! It's clearly a game to you. You've trained me to ignore my own sorrow after the opening scene and are now punishing me for not being empathetic with a fictional character!
Quote
"That's what art is meant to do anyway. Art is meant to rethink your position in life. That's the mirror to nature principle".
My position is that art is about intent rather than impact. Intentionality is how you create something that's greater than the sum of its parts, not by trawling Discord for ideas. I'm fine with following an artist into some dark places if the craft is good enough that I can tell what's being actually said by the author. (Disco Elysium made me cry and I love that game for it; at no point did I question whether the game wanted me to take it seriously.) But if the artist wants to explore dark corners with nothing meaningful to say, they will end up saying awful things by default. Things like "this dark corner has nothing I find scary, you people must have a problem."
To answer the thread's actual question : I don't know if BG3 was overly sexualized, but I feel it was poorly sexualized, with either no or contradictory thematic relevance to the rest of the game.