I agree it should increment in any given season/tier.

In general I do think we need a higher cap as if you play something for a couple weeks and buy something or other and in the end need to change jobs for whatever reason ( Don't enjoy the job you've been playing anymore, find something more fun, filling a different role in a friend/static group.)

I can say from experience i just came back about a month ago starting playing again to raid with friends and just went back to what I was playing before hand. After playing a few weeks again just realized I did not enjoy it anymore and wanted to try something else out and have switched. Those 4 weeks of tomes that i got and bought gear with for the first job are now just wasted.

Either a higher cap to make a transition to a new class not as bad.
or even say a vendor you could recycle your tome gear into that gets your tomes back to retry.