Some of mine maybe aren’t that niche anymore, but:
Retro computing: no one needs more than 640k. Maybe no one needs more than 64k. Those old systems were the last time a single programmer could have control over the entire machine at a low level.
Ham radio: Oftentimes called a dying hobby, but a great foray into electronics in general, and also a pretty nice community (save for a few curmudgeons).
Analog audio: often thought of as a boutique thing, but really isn’t. Lots of old equipment ready to be restored that can give you really unique auditory experiences.
Plastic modeling: especially if you start from a kit but add things to it, or if you build from scratch, or hell, even if you just build a kit as intended, there is a huge amount of personal expression and creativity.
Some of mine maybe aren’t that niche anymore, but:
Retro computing: no one needs more than 640k. Maybe no one needs more than 64k. Those old systems were the last time a single programmer could have control over the entire machine at a low level.
Ham radio: Oftentimes called a dying hobby, but a great foray into electronics in general, and also a pretty nice community (save for a few curmudgeons).
Analog audio: often thought of as a boutique thing, but really isn’t. Lots of old equipment ready to be restored that can give you really unique auditory experiences.
Plastic modeling: especially if you start from a kit but add things to it, or if you build from scratch, or hell, even if you just build a kit as intended, there is a huge amount of personal expression and creativity.