i like it.
eventually the cap will be 99.
in the same way that you can attach 1 materia per gear part for certain, but as many as 5, or food effects and such,
a rank 50 battle class player will never be near as strong as one with the complete package.
Even with jobs, the purest complete player will need every battle class at 50,
which means eventually EVERY battle class at 99.

In continuation, how is a player without crafting and gathering levels at 50 to survive?
they must rely on other players.

However, i do think there is an issue necessarily, if rank 10-40 content is so quickly missed that players will never have time to immerse themselves in the content.