Self-hosting is having a moment, even if it's hard to define exactly what it is.
It's a niche that goes beyond regular computing devices and networks but falls short of a full-on home lab. (Most home labs involve self-hosting, but not all self-hosting makes for a home lab.) It adds privacy, provides DRM-free alternatives, and reduces advertising. It's often touted as a way to get more out of your network-attached storage (NAS), but it's much more than just backup and media streaming.
Is self-hosting just running services on your network for which most people rely on cloud companies? Broadly, yes. But take a look at the selfh.st site/podcast/newsletter, the r/selfhosted subreddit, and all the GitHub project pages that link to one another, and you'll also find things that no cloud provider offers.