TL;DR – Western pop groups aren't like Korean pop groups and were never going to work for the most part.
I don't personally know if I'd say they were run like a k-pop group. I can't really think of any western boy or girl group that was ever like their Korean equivalents. I say Korean because, really, not even other such groups in Asia are like k-pop groups. They're their own thing, save for when the usual human negativity rears its ugly head. But that can't be helped no matter where you are in the world.
I'd say the closest western group would be Take That from the UK, at least in their later years, when they all mellowed out and matured.
But for the most part, I feel like western groups were a series of failed experiments in trying to cram people with wildly different backgrounds and skillsets into boxes and ordering them to make it work. Take That learned to make it work because they grew up.
I'm not implying, 'Oh, right, because Asians are so docile and never rock the boat . . .' I'm East Asian myself, and I hate when people bring this up. Because yes, even though all Asian societies are different, very generally speaking we are taught not to rock the boat – but that's still not all of what we are, obviously, you know? I just think there's something about the k-pop idols that make them great at teamwork and still great on an individual level, so everything just clicks.
And obviously, a lot of the times, it still doesn't. But again, that's human nature. I just don't think western individualism gets along well with the concept of idol groups. You certainly don't see them going from first gen to second gen all the way up to fourth like in k-pop.
If Pussycat Dolls were run like a k-pop group, I feel like some actual effort would have been put into making sure everyone could sing and dance. Line distribution could still have been problematic, certainly, but I think it'd have been somewhat better than what we actually got.
Even if the members all ended up hating each other, fandoms and antis would up being toxic, the company wound up being toxic, too, I think there would have been effort, at least initially, to make them work. But western pop groups have always just been, 'Hey, these people are hot. They look good together. They can . . . sorta sing? And dance? Well, I dunno, just sign them up already! This will totally work!'
And I guess it kind of does, but there's just never much foresight or care, and as a result, lots of built-up drama and resentment gets made instead.
Actually, I sat back a moment and had a thought, and if I'm being honest, if there's any western countries that could potentially make pop groups a thing, it's the Nordic countries. They could do it, I'm sure. I dunno, does ABBA count? Never really listened to them.