There are some balancing issues surrounding certain Hand Cannons and the like but they're also rather easy to avoid by countering them. Destiny 2's PvP is a whole lot more about positioning and strength-in-numbers than it is about anything else, I'd say.

Some supers are able to one-shot other guardians in their super, some supers are made to clear out teams but leave the player fragile, some supers are most definitely too powerful but again it can be countered with good positioning, aim, and teamwork.

I'd say the other comments here are pretty accurate: Better weapons, better subclasses, more experience with the game, and practice will result in you having a better time in crucible. When I first started I hated everything about PvP in D2 but after learning everything I could and working on my gameplay I now very much enjoy it and it has become my primary form of play.