Beanie Babies were something a little different though because they were a stand-alone item, this is more like cosmetics in video games where it's attached to the popularity/longevity of the game (even then that's not quite accurate because artisan keycap supply is more finite). Also, because artisan keycap makers typically engage in the same space (GH/mk) as the "consumer", there's an emotional component involved as well, and for the foreseeable future the elements of that are the only real thing that could collapse that maker's market (ie. the maker's community attachment turning negative, or the community they engage in itself dies).
I will say, that as someone whose grandmother was addicted to the Beanie Baby fad, I recommend that anyone that involves themselves in collecting any sort of non-necessity (ie. artisans), stop yourself and reflect on your situation. Ask yourself why you do it, think about what sacrifices you have made/will make to build your collection, and figure out what your long-term goal with it is/if you'll still appreciate it should your situation change. In general, it's certainly not "wrong" to be a collector of something, but it is very easy to get caught up in hobbies like this that have grown social and persuade yourself into spending time/money on it that you realistically shouldn't be for the "wrong" reasons.