There is no way you should get rank in BJJ without knowing the gi techniques too. That means you should train in the gi too. Purely no-gi ranks are totally separate from BJJ.
And don't say there aren't ranks in wrestling. Team captains/Varsity players/JV players are also ranks. Hookers, shooters, and any kind of title is a rank. And like BJJ ranks, those are sometimes political and awarded for the wrong reasons. And like BJJ ranks, one shouldn't train to be a varsity wrestler or team captain. Instead, one should try to be the best wrestler they can be and try to be a varsity wrestler so they can compete again better opponents and win states (for example).