True, but they seem to have been ahead on 10nm until they weren't, which calls into question claims about 7nm.

Then there's the question of why they aren't skipping 10nm if 7nm is so ahead.

And theres the question of why they can't 'scale up' their 7nm to do 10nm.

Presumably 10nm is cheaper to produce, so they can use that to make lower-end processors.

Yes, they are substantially different processes.