I imagine the cap is at 10 largely to avoid having to deal with 6th level spells.
Yep; but for some people here a single cast of a 6th tier spell per long rest too overpowered and believe that we should spend 80 hours slaying kobolds in sword coast
It's not how many times you can cast it, but what that cast can do and how hard it would be to program it.
At the very least, Transport Via Plants, Programmed Illusion, Move Earth and Wind Walk would have to be out.
