Yes anon we can't cheat mathematics. 300 Blackout's main problem is the bullet diameter is so low yet the sectional density is so high you are inevitably just going to ice pick a 30 caliber hole through the target with subs. 338 ARC tries to address this with insignificant advantages

I dare say if you live in a forested area or an urban area (~85% of the US population) then a PCC AR in 10mm or 45 makes far more sense than any sort of 60k PSI rifle chambering.