Every competitive game has a ranking system. I do not see any issue playing and trying to improve, just reduce your expectations.

A lot of 20 year olds are trash in a lot of competitive games

If a service costs money, and you take that service for free without permission it is stealing. If I rent a car I don’t own it. Is it not stealing to hijack a rental car for a few hours?

You can’t have your cake and eat it too. You steal because it is easier or cheaper. Thats it.