JACK-OF-ALL-TRADES
A guy who can do a bunch of stuff, but none of it very well. He's like a broken toaster, works, but not great.
My uncle can fix cars, paint houses, and cook like a chef, but he can't do any of them well.
She can code, design, and dance, but none of it is good enough to make money.
He can mow lawns, build decks, and fix plumbing, but he can't do any of it without swearing.