Are 13X5 mob’s less frequent in hardware units? If so, why?
They don't exist (outside of support of CNAFR) because the personnel have been put in a protective status. It was like that before, then it wasn't, now it is again. Some individuals will still MOB because they a) volunteer or b) (the more common one) the unit itself is in need of a body so the billet (or squadron) is mobilized (See: HSC-8x, although it happens elsewhere, too).
This stuff never changes with it either. But for what its worth, if you can learn to live with the total lack of order with admin and just drive things yourself, you will get a lot out of it and and enjoy your time. There's great people, some great work, and lots to be had from the experience. Just don't expect the admin side to knock things out of the park.