Seems fair, but doesnt feel like it

In my recent game, (what an awful way to start a post, the rest is probably going to be heavily influenced by emotion, you are encouraged to discredit all further opinion) I had my lane opponent disconnect shortly after being pushed from the lane by trades gone badly for him. He was gone from levels 2 - 10 and was pushed out of lane again before being able to get any cs.

Realising he couldnt stay bot lane he rotated to toplane against an increadibly bad 0/5/0 nasus who was content letting him freefarm. In a matter of about 5 minutes he fully caught up in levels, finished a Trinity Force and had gotten 2 kills.

I know catch up exp is a game mechanic to help make the game feel competitive even after having a disconnect but it just feels to me like the catch up exp makes gaining a level lead almost insignificant.

Being 2 or 3 levels ahead doesnt mean anything if the guy can catch up in 1 wave due to getting catch up exp. And I know thats not a real thing, and that the exp of minions slowly increases throughout the game and that is why you gain exp faster the later the game gets. Its just annoying when I thought I was going to win for sure having gained a 9 level lead over my lane opponent only to have him fully catch up and later win.