People are mining moons. Moon belts are being mined. Its still viable as in terms of mining the minerals to supplement builds of anything.
The quantum core update will reduce station ownership by a lot because single owners know they cant defend the stations. They would be unanchoring/selling stations before Dec/jan hits
Zeolites (and Bitumens to some extent) are a good source of pyerite and of course big rocks, other than that hisec moon ore is only viable if you need the hisec varieties of moongoo in bulk.
If your corp has an Athanor then you do have a lot of ore in one place which you can blitz, this can offset any logistics needed for belt mining and the small rock size. But then you need a corp and an organised mining fleet.
No moon mining is no longer viable. The moon goo is next to worthless and not being able to compress the moon ore has killed transporting it too sell.
Save yourself some isk and headache. Forget moon mining in high sec. Since the cores are SO EXPENSIVE and high sec stations are not combat multiplier, just forget it.