The great thing about becoming a plumber is that it doesn't require a degree, although it does require training. Unlike student teaching though, for example, you actually get paid for your training. A paid apprenticeship, if you will. That's a sweet deal, even if you have to mess with some nasty stuff. Again, no one is going to pay you lots of money to play with puppies. That's just not a thing. If you want to make money, it requires work.
I don't think it should be any surprise that plumbers make good money. When's the last time you were excited to call a plumber? It usually means dropping big bucks. If a plumber can get a contract with a building or a restaurant, they could be set for quite a while with repeat business.