I don't know what it is like on reddit, but I feel the discourse around Astarion on yt is a bit on the toxic side in general. You mention nasty spawn support under ascended videos, the same is true the other way around. I have gotten a comment about how vile it is to not ascend poor Astarion under a comment that wasn't even about Astarion, and got some pretty bitchy reply to something that was mostly about how the writing for stopping the ritual was handled by a Spawn fan. There just doesn't seem to much room for discussion unless you 100% agree with the view of a video's creator - which means there isn't room for discussion at all.
Yeah, some people are getting a bit too invested in a fictional character, to a degree, where it just isn't healthy anymore. I think most BG3 fans are pretty nice in general, but you always have toxicity in such a big fandom. Live and let live is my motto.
And back to topic: I liked romancing Astarion with my gnome bard lady. Remember how he makes that not so nice comment in act 1 about gnomes? Well, he apologises profoundly for it,when you go to act 2 and establish the relationship. That was really well done and nice of the writers to include that, despite gnomes being among the least played races ( which is sad, they are awesome). I also like the kiss animation for him and a small race Tav ( and I'm romantic as a stone normally - I didn't even notice, the kiss animation was broken after that one patch or hotfix)
"We are all stories in the end. Just make it a good one."