Murder and sex are not the same, in case you didn't know wink
By the way fun fact: Murder is also not as graphic in the game as it is in real life. We could show necks being slashed close up with great graphic detail, or see guts spill out as our enemies cry and writhe in horrific pain, but we don't, and that's a good thing.
If we made murder too realistic and explicit in the game, most people wouldn't play it because it would make us feel bad. There is a reason why the enemies we kill are just treated as puppets without much of a personality, or evil.
If we don't portray murder and killing as ultra-realistic, why should we do the same with sex?

Fade to black is good, because it leaves things to the imagination. Let's imagine that I wanna have sex with Astarion and the game gives me a scene where he has sex with my male character as a top. But I wanna be top and I want Astarion to be a bottom. Should I write a complaint about how Larian didn't cater to my specific expectations?

Fade to black is once again superior because everyone can just project their own expectations into it.