There are (in my opinion) 2 viewpoints to the “friend zone”
1) You are always there for that person. Give them everything you can possibly give to show how you feel about them. But you’ve gotten to the point where they don’t want to endanger the relationship that has already been established because they don’t want to lose you.
2) That person either A) doesn’t feel the same. B) they just keep you around for their own convenience because you have shown them that you’ll still be there when everyone else leaves. C) (maybe) They have led you on for a while and when they don’t want to come off as an asshole/bitch they just drag you along instead of putting you out of your fucking misery.