What is a niche hobby of yours that you are fascinated by and would like to share with others?
I'll start. I have recently gotten into 3D printing, and, while incredibly frustrating sometimes, there's nothing more rewarding than getting a perfect print.
I like buying LEGO minifigures and then designing/building biomes for them to inhabit. I use BrickLink Studio to design the builds and then upload my parts list to BrickLink to get used bricks to build them. I also post them on Rebrickable for free, but I've fallen behind and need to post more on there.