Fez gets too much love
I do like him as a character of course, and his IRL death is tragic but lets set that aside.
He always claims to not want to contribute to Rues addiction but he only does this when she needs him.
He continues to sell her drugs aside from that and does not do anything to help her as a friend who cares about her would.
Instead when she is at her worst and dope sick from the drugs HE sells her, that HE profits from he treats her like a street rat and refuses to give her anything.
This is portrayed as him being noble and caring but in reality he is just being a shit drug dealer and a horrible friend. Even if you do view it as him trying to save her or something it is completely voided by the fact that he just continues to keep selling her drugs.