I am paragon 64 and I am still getting better gear every as I am leveling up. Playing several hours a day I have several triple stats legendaries. Judging from my challenge rift progress, the only thing matters is damage. Main stat affecting it is combat rating. Gems do not matter much unless u invest significant amount $$. I have bought a battle pass and some packages totalling usd 100 and did not seen much effect in challenge rifts and battleground.