Personally, I can only tolerate yandere up to the "has a GPS tracker on me" level.

A little clinginess is fine, but anything beyond that and I can start feeling uncomfortable with the character, even though they're fictional.
That said, as a viewer, I actually find extreme yandere behavior pretty entertaining in fiction. Seeing the heroine being loved and obsessed over to that degree can be fascinating, and honestly, a little enviable too. There's something fun about watching someone love the heroine THAT much when you're safely sitting outside the situation.
But if I were actually in the heroine's position? Absolutely not. Put me in a cage and I'm already gone.
I think it's probably because I really value my freedom. I can enjoy possessiveness and obsession as a fictional fantasy, but I don't want that kind of love in real life. For me, there's a very clear line between "I love you so much that I'm obsessed with you" and "you no longer have a life outside of me."