Even worse when you show you learn fast and are competent and you eventually realize that you're the dumbass stuck taking care of all the hard stuff for the same salary...
I'm not one to defend companies at all, but in my experience when I can actually prove I'm "better" than my coworkers I've gotten the raises I've asked for. I make every attempt to prove my value, come with the argument, and if they deny me then I quit after I've found something else. (I'm a blue collar schmuck so it's not like I'm some high demand tech bro.)
You have to ask, they will never just give you a raise.
That said I've never worked for a corporation other than my retail days, but you'd never be able to prove any "value" in those situations anyway.
It's an issue with union jobs though, I'm currently pushing for the creation of a new position at a higher level to recognize the fact that although everyone might be trained to do the same things, some people clearly take care of stuff most employees couldn't handle.
That or just call HR and pretend to be a complaining customer. Use *67 or text free. I did that ONCE and had a new boss in a month. (Yes, they deserved it)
I try at my job because if I'm going to do something for 40 hours a week, I'd rather take joy in being good at it than stew in resentment for most of my waking hours