Plus, there's this thing where there's no one team responsible for all nodes. Whoever worked on 7nm will not be working on 5nm, but on 3nm instead. 5nm is already being worked on by the team that did 14nm. That's how things are usually set up in this industry.
Somewhat unrelated, but it's also what will most likely make weird for Intel, when their 7nm node will be ready shortly after they figure out 10nm.
And it's going to be a blast about 5 years from now when everybody hits the physical limits of Si and we all get stuck on 2 or 3nm, while fabs shrink various parts of the transistor. If you think 14nm+++++ was embarrassing, just wait for 3nm++++++++++++++