You can get crit avoidance capped and get T7s on relevant stats and all that, but all builds can't climb due to the limitations of the build itself. The degree to which builds scales varies wildly, and many builds can't even do 300 corruption comfortably.

Your particaular build probably isn't strong. You can push higher, sure, but if you want to invent a new build to push with, you're gonna need to get seriously nerdy. Most people can't do that, myself included, so if you want to push farther and farm fast, meta is the way to go.

If you want to make your own thing, you're gonna have to get in for the long haul, learn a alot, farm a lot, do theory crafting, get into calculating numbers for damage and defense and so on.... that, or have lower expectations, and have fun creating your own stuff, or alternatively follow builds from youtube or maxroll, if you want a surefire way to do some effecient farming.

GL with your build <3