And if you set them to different hotbars, you can separate out class-specific and general sections (since whether to share between classes is hotbar specific). For example, I have L1+R1 bring up the left side of one hotbar, which is shared between classes and has general stuff like Return, Sprint, Mount Roulette, gysahl greens, my favorite minion, and a couple emote macros, while R1+L1 brings up the right side of a different hotbar, which is class specific and provides some overflow room for class skills that don't fit on hotbar 1 or that are more situational rather than my main attack/craft skills. (Then both of these hotbars are excluded from the ones I'll cycle through, since the L1+R1 or R1+L1 gives me access to the parts of them I use.)

In total, you can have up to 32 skills available without any hotbar switching (more obviously if you also switch hotbars). And you can choose whether 0, 8, 16, 24, or all 32 are class-specific.

I have some issues with the rest of the controller setup in this game (as discussed in this thread), but I think SE did quite a good job with the cross-hotbars. With a bit of tweaking to find the setup you like, they can be quite versatile.