Championships mean something to some people. Every rule in sports is a "made up concept", it doesn't make them any less valid. You used to have to earn a title shot, and the road to get there was harder than the one fight. Champions used to defend, and defenses were difficult, because the entire division was working towards beating you.
You may not feel this way, and these days, it looks like you're right, but being at the top of the hill used to mean something.
Khabib is the real champion here, no doubt about it. Conor didn't defend, the belt was taken away, and Khabib beat who they put in front of him. It doesn't matter... At all... That he didn't fight the number two guy. He was supposed to, and that guy dropped, so he fought the best guy they could find on short notice. Now Khabib's the champion, and he is immediately doing what Conor never did.
Conor absolutely should not be parading these belts. He crapped on them by failing to defend them, choosing instead to chase the bigger and better deal.