that re-posting someone’s artwork without their permission is not “helping them” or “showing your appreciation” it’s straight up theft. You are stealing. End of discussion. “Fair use” does not protect you. Crediting does not protect you or make you any less of a thief.
And if an artist comes to you and asks you to take it down and your first response is to be an utter prick and go on about what ~you~ are doing for ~them~ then go step on a lego you entitled little shit.
(feel free to translate this because this problem is with more than just English speakers)