That's assuming diminishing returns won't hit hard. If a 10x smaller local model is 95%(Whatever that means) as good as the remote model it makes sense to use local models most of the time. It remains to be seen if that will happen but it's certainly not unthinkable imp.

It's really task-dependent, text summarization and grammar corrections are fine with local models. I posit any tasks that are 'arms race-y' (image generation, creative text generation) are going to be offloaded to servers, as there's no 'good enough' bar above which they can't improve.