What was the problem with moores law in the future?

Answer 1

For it to continue forever it would require making transistors smaller than a single atom, which is obviously impossible.

However long before then it would require making transistors containing fewer atoms than are required for a material to exhibit its bulk properties. Since the property of semiconductivity is a bulk property and transistors require it to operate, while one could try to make transistors that small it is impossible for them to work.

However long before then there are issues of practicality that make fabrication of reliable integrated circuits questionable as they get progressively smaller in internal dimensions.