I did some hair testing:
Evee:
Cycles and HairBSDF
Noodle monster (Eevee and Principle BSDP)! He is missing meat balls…
Before it was close to a few hundred thousand faces and vertices. now it is only 50 thousand faces, and less than 30 thousand verts. The computer is enjoying these much better.
It was “decimate” modifier that I used, not “simplify” which does not exist 
of course 