had to comment right away,
there are a few that are herbivores, or omnivores with a strong plant preference.
-gold nugget pleco
there's over 400 different kinds of pleco's out there. picking a pleco for algae control because it's a pleco, ... why not pick a goldfish, i don't doubt that the goldfish will eat the dreaded cladophora algae that nothing else will touch.
I agree that you should pick and chose the pleco for algae control well, but ...
Gold nuggets and bushy nose plecos are extremely effective and do not harm healthy plants. How do I know? I actually have them in several tanks.
So do other folks without issues. Obviously you will not put a Panaque into a planted tank, no one here is suggesting such obvious hyperbole.
Example of my tank with gold nuggets
Same for Otto cats and the like, there are many species that are effective, whiptails, Farowella, Sturisoma etc etc.