From what I understand, the way secondary stats work (and, of course, the things derived from them) is entirely dependent on your level.

You could have 2500 crit, and that would mean (just spitballing here) like 30% crit if you're level 70, but only 20% crit if you're level 80.

I imagine they occlude those numbers because "yay, I levelled up! Why did my crit chance fall through the floor?" feels really bad. By the same token, a player at level 30 won't have something like 5% crit chance.

It's a good system from a backend perspective. You get to continually give the players a sense of "more is better", while also not eventually capping out on critical chance, direct hit chance, etc. Practically essential in a vertical progression system, in my opinion.

As to whether the final numbers should be somehow public, even if through an official wiki, I don't really have an opinion. The playerbase figures it out quick enough, and that's good enough for me.

I never really think about it all that much, personally. As a red mage, I avoid spell speed and rush crit. 'tis a simple life.