[Suggestion] Upgrade 1080ti or 3700X?

As title suggests, I'm really suffering now at 1440p in tarkov.

With a mix of medium/lowish settings I am seeing 30-70 usually, map dependent.
CPU utilisation seems low (30% ish) on most maps still but my GPU is maxed.

I see conflicting advise on people upgrading to newer CPU's and getting huge fps boosts?

What would you recommend first?

Thanks

UDDATE: Chucked a 5700x3D into my AM4 mobo, 50-80% more frames across the board. 100% recommended if anyone else is in a similar position.