I had a similar problem. I played for a few days right when the game first came out and then deleted it. Nearly 1.5 years later (earlier this year) I started playing again. This time, I am staying for good. In my arena, though, everyone above rank 750 in arena has zetas, gear level XI, level 85, latest meta toons, GK, the works. I have played every day since I started back, and I do everything there is to do. Even with that, I am not yet level 85, I have no zetas, Only one character at gear XI, none at X, and two at IX.
It makes progressing harder for me (due to less crystals), but since it has always been like this for me, I am used to it. In my opinion, it will just be more rewarding to finally crack top 100 someday.