
From what I remember when I followed k-pop stars a lot of the fan base would have a problem if their bias was dating. It's like they feel disillusioned by it and like the star is no longer their's in a way. Cause now they are with someone else officially. Also I feel like there's some jealousy there. Fans can be really really possessive and do/say some really fucked up shit at times.
The fans in the USA of most actors are no where near that level. I think the best comparison would be like Taylor Swift in how her fan base all of a sudden started watching football cause she was dating a footbal player. Or how they would feel insulted if someone said something bad about her.

In a way yes, that's kinda it cause they feel they provide all their love and support for the artist. They buy their merchandise, follow their events, and may even take the time to promote their bias online to others. They put a lot in, though noone specifically asks them to....it's also why some artist in the past have had creepy fans and stalkers at times.
I can't say how things are now as I dont really follow or keep up with too much of it. I would hope things have gotten better and companies do more to keep things under control as well as their artists safe but who is to say. Alot of the stuff you see in manga, webtoons, anime, and k-dramas are a dramatization of things that have actually happened in the past. Sometimes not even that dramatized when it comes to artist, bullying, and corruption.
Basically every culture has their issues :P
I don't follow k news or like controversies in general I have heard of dating scandals bleh bleh bleh but I assumed it was more of a dating a minor, age gap maybe lgbtq+ rels idk cheating shit but a quick search on the internet makes me believe they make a great deal out of any dating scene? Like is that true? Seriously? They mind ppl dating normally? Seriously?