Fair enough, wave 30 is basically endgame for the top 1%. But as far as my current build goes I'd think that this would be enough for T16 rare reds but it's not. I've got spell suppression, max resists (except for chaos), capped block, and decent phys reduction through armour and charges on hit. What am I missing?

I'm not following a guide. I threw this one together myself in an effort to better understand the systems underpinning the game