How have issues in the new rift not been fixed?

I ran on the old summoners rift at upwards of 150 frames per second with everything maxed out. With this new rift, I get into the low 10s-20s in the middle of team fights, with no real reason for it. This being a new addition, i would normally be perfectly accepting of it. But the fact that this is enabled on ranked too is a joke, considering i don't have a choice but to play on the new rift, and I can't play reasonably during team fights. Not to mention every single character has a giant red/blue square around them 99% of the time, as well as the fact that I can't even load into game without ending the process 50% of the time. This was on the PBE for months, how do I still have extensive issues on a high-end machine?

tl;dr riot you force us to play on buggy rift in ranked what were you actually thinking