STR Stacking Assassin Kinetic Blast/Power Siphon Build Help

so it's been a few leagues since I played and I'm just messing around in Standard while I wait for the new league. I have this old char that I'm building.

I feel really squishy when mapping past anything t10, is there a reason why? I vaguely know that this str stacking build was nerfed a while ago, but is it also less tanky now or do I just have bad mechanics.

My POB: https://pastebin.com/jifnVBkF