I think the difference is whether the content is truly infinite or not. If there's enough content such that you could spend an unhealthy amount of time scrollin

I think the difference is whether the content is truly infinite or not. If there's enough content such that you could spend an unhealthy amount of time scrolling, then you are sacrificing your users well being for engagement. If there's a finite amount of items, the "expand the list as you scroll" approach is pretty reasonable. At that point you can't really call it "infinite scroll" anymore