It should be called out that the companions are all quite shallow and forgetable compared to many other RPGs and that Larian in order to distract from that seem to have specifically designed them for rule 34 and simping/thirsting which many fans seem to gladly indulge in considering even here most posts about the companions are about who has sex with whom.
This is not a good development for rpgs in general.
They are certainly lacking in content, I'll agree on that. But act 3, where the romances should blossom so to say, in general is lacking on origin companion content, not just romance-specific. Add all the missing or wrong triggers for the content that does exist and suddenly you have a very bare bones experience.
Yes, I think that the little erotic sex fantasy side stories are what they are and there for that audience, they really don't play a big part in the grand scheme of things. No one ever really cared about consistency in porn, so why expect it from porn within a game?
I would disagree that they're forgettable erotic sex fantasy side stories. If anything, isn't that what people are arguing against here, with the Halsin/Shadowheart/Astarion scenario turning it into that if you indulge (or even just acknowledge Halsin's existence as a non-campbound companion)?
Both Shadowheart and Astarion have very tragic yet wholesome stories, especially if you romance them. And you can 'unfix' both, leading to your romance's downfall. And while Astarion uses sex as a tool in act 1, Shadowheart can in fact have no sex scene depending on your choices, and otherwise gets a very late one.
Wyll doesn't even have a sex scene and yet what you get for his romance is memorable. It just needs more content. A lot more.
Lae'zel's romance turns into a lovely story if you ignore the sex out of the blue at the start. Though she's the only one that does that, so it's acceptable.
Karlach's is a story about knowing and accepting upcoming loss and making the most of the situation at hand. If you want to, you can avoid sex with her and have it be a caring relationship instead.
Gale I'm not entirely sure. His romance bugged out for me in my playthroughs so far. I know his non-romance scene in act 2 is great, though, as a heart to heart moment between friends.
Minthara's romance start very much feels like a "good job on being evil, enjoy your reward to compensate for the losses" sex scene in act 1, I agree on that.
The only time I feel like most companions are thirsting is around halfway act 1, where you have to turn them all down. Some would've preferred it if it were more player driven who you start romance with, but people do enjoy it when the companion isn't just interested in you if you show interest in them first. It's not bad for them to have some autonomy.
Halsin is pretty much the only one that's suddenly all about sex in act 3 and has no other content besides. And even then, it's not much to begin with. You get one scene, you get him forcing himself into the drows scene, and that's where it ends. The act still has like 30 hours left at that point. So he does fit that description perfectly in act 3. But not during act 1 and act 2.