1-50 is just a tutorial. At levels 51-60, exp gains get slower and mobs get harder. Grind spots also become contested. Open world pvp automatically becomes enabled upon hitting level 45, which allows you to Pk or be Pk'd. Upgrading gear past +5 or +7 is rng ( current BiS is +15). The power difference in very noticable in between geared and ungeared players as well as player level. TL;DR: Yes the game gets significantly harder past level 50. Hardcore players will always be at the top. But it's still possible to play casually, because there are so many other things to do.