Most anime’s are always clones within the span of that decade.
Consider Pokémon, Digimon, etc
When something becomes popular, people try to copy it and get on the hype bandwagon to make money.
Maxbot could be considered a somewhat copy of the then popular Gundam. In the sense it’s a mecha fighting other mechas etc.
Never seen Devilman so I can’t say anything about that, but you are passing judgement based on the cover art.
I try to get at least 3 episodes in, into an anime before I decide if it’s interesting enough to keep watching or not.
Consider watching at least the first 2 before you pass judgement. You might find yourself actually liking titles you dismissed earlier and didn’t give them a chance, as have I admittedly.