It's sad because as a fan, you want to see these shows have a lasting impact and therefore continue for as long as the actors are happy to be there but you could really see the turning point with season 5 in Donna and part of me wonders if Tori was trying to seize the spotlight now that she didn't have Shannen as a screen partner...
Because Donna had basically always been defined by her friendships with Kelly and Brenda, and now that Kelly was with Brandon and Brenda was "in London" aka never coming back, Tori got to play Donna as a singular person who - without David - was trying to look for some sense of identity. Then she met Ray, and it all failed in a spectacularly awful fashion.
