Always thought friendzone was when one person was exploiting the power differential caused by non-reciprocated romantic feelings and calling it a “friendship” when it’s really an abusive sort of relationship.
If someone has unrequited feelings for you and is struggling to get over it then you need to be clear with your rejection of them and give them space to get over it. If they reject your rejection then they are being problematic. But if you can’t give them space then you are being selfish.
Romantic rejection involves a grieving process and it’s normal to need space to go through it. If the person who rejects you can’t give you that space you need then they are not your friend.