I'm in a position similar to Sivers, in that I don't have a permanent home, and I'm unlikely to find one in the near future. Like him I'm in a furnished apartment with barely any stuff of my own save for clothes, a laptop, a phone, a kindle, and a handful of other belongings. Some days I really yearn for a place of my own, and the things I could have in there...
But when I read someone saying they cannot wrap their head around how anyone could be fulfilled with living like Sivers... I feel obliged to respond. This is how my life is, and it's fine, I'm quite happy.
I play music with my friends in a rental rehearsal space, I meditate, I take photos with my phone, I code on my laptop, I discuss things, I read, all those things I listed. It's not some awful deprived life of poverty just because I don't have several bags of camera equipment!
Some of the more esoteric hobbies I've gotten into have included amateur telescope making, ham radio, long-range precision reloading, and shed construction, all of which are very tool-dependent. The more and better tools you have, the more capable you are in the hobby, the better your results, and the more satisfying it is. Sure, some hobbies are more amenable to getting farther along in them with having less stuff, but that doesn't help you if you end up interested in something that is tool-dependent.