Call it what it is........

Why are 29er wheels (700c) really like 24.5” (622c) and a 26” wheel (650c) more like 22” (559c)? Yes, I know if you add on the 2” tire you get 26” tire but then why call it a 650c wheel? And even if you add on a huge tube town’y tire on a 700c you’ll never get close to 700…..so what the deal?