Making things, mostly.
Lots of crafts like knitting, crochet, cross stitch, sewing, felting, origami, faffing about with clay, etc etc. And gamedev which I basically think of as the same sort of hobby because it's just making a different sort of thing.
Making YouTube videos about all of the above, in defiance of the algorithm gods.
Reading any and all scifi I can get my hands on, plus the Discworld series just over and over again endlessly on a loop.
Also the amount of time I spend on Mastodon and Lemmy probably means it counts as a rather lame hobby at this point...