>>319246174
it does actually scale to a point. I think it could use some improvement, for sure.
the only things that will fully block an avatar when they exceed whatever you've set it to: 

Polygons
# of Skinned Meshes, Meshes, Bones. 

for everything else, that feature is just removed depending on what you set the minimum to. 
So for example, if you set it to medium, anything more than 8 particle systems will just disable all the particle systems and leave everything else on.
Same thing with dynamic bone, anything over 16 components or 32 transforms will just disable dynamicbone for that person. 
1 cloth system at 100 verts is the max or the cloth gets disabled, 8 audio sources and the audio gets disabled, etc. 

It's a bit deeper than you might imagine. It could certainly use more intelligent situational profiling, we agree. Plus cloth is cheap now since 2018.4