Coming up with a character and playing it in such a way that it's cool and not stupid, not to slip into nonsense and not to become someone who spoils the game and immersion of the whole party, I think, is a very difficult task.
Though, you have to keep in mind. Not everyone wants to play D&D and be super cereal and cool.
Sometimes people just want to mess around.
Hence things like lusty Bards, murderhobos, 3 INT Barbarians who cannot communicate with anything, people homebrewing crazy OP things etc.
It's an aspect of D&D that can't be discounted. The ability to do what you want, allows people to joke around. This ranges from the game derailing murderhobo streaks (And subsequent "Rocks fall and everyone dies" DM responses), to things like playing silly characters but in a reasonable way (Like for example Sir Bearington)
Not everyone likes to play this way, many like a more serious approach. But it's popular enough to create pop culture references to the types of players who do that stuff.
I'll also say that the two really aren't mutually exclusive. Sometimes you'll get groups who have stretches of really silly, jokey stuff, then they'll get back into serious roleplay and intense story stuff. I'd argue that that's probably the default for most ttrpgs unless you're being really strict about it. Very few groups want to be constantly silly for an entire campaign and very few want to just be constantly serious. Both are exhausting for different reasons if they go on long enough.
As for inherent horniness in the hobby, I just finished watching the first ever season of Dimension 20 I've ever watched. I started with "The Seven," can recommend it. The season was about an adventuring party of high school girls and it was the most consistently horny actual play I've ever seen/listened to. There were no inter-party romances but the cast and their characters were regularly getting VERY vocal about how hot various NPCs were, two occasions where the PCs actually went off to have sex, and this was all mixed with incredible hilarity and a lot of intense moments of roleplay and emotional scenes that genuinely had impact. I'd argue that that was actually more consistently horny than BG3. It didn't have the intense peaks that BG3 did, but the horniness was more present throughout the production. So yeah, my opinion once again is that BG3 isn't nearly as horny as some people say. It's definitely sexualized, but not to any absurd degree.
