First of all, vinyl is still relatively niche in absolute terms. Second of all, the popularity of vinyl, such as it is, has absolutely nothing to do with availability. It's largely driven by a kind of retro nostalgia (as the technology itself is, of course, inferior from a technical sense of faithful reproduction) plus a desire for personal physical ownership of something.
First of all, vinyl is still relatively niche in absolute terms. Second of all, the popularity of vinyl, such as it is, has absolutely nothing to do with availability. It's largely driven by a kind of retro nostalgia (as the technology itself is, of course, inferior from a technical sense of faithful reproduction) plus a desire for personal physical ownership of something.