Question for y'all...
Getting back into Destiny for the first time in about eight months. I really only enjoy playing Crucible. I'm a level 28. Am I ever going to level up again if I only stick to Crucible?
Yes! Right now you can get up to level 33 through gear sold by the various Crucible vendors (Crucible, Future War Cult, New Monarchy, Dead Orbit) with crucible marks that you earn from playing crucible. You need to rank up your reputation with any of them to rank 2 to purchase armor.
To get to the level cap of 34 doing only Crucible, you will need etheric light from Iron Banner or Trials of Osiris or light level 42 gear from Trials.