With a PDS, you have something that's better than a trad filesystem: standardized, built for programmatic interaction, built for networking, handles text and blobs, can be arbitrarily extended, extensions are discoverable.
The basic mode of interaction being filtering on the firehose is also key, since you decouple the front end from the backend; you can keep as much data on your PDS as you like, run all the lexicons you want, and you don't have to compromise or bow to a single overarching idea of what an atom is. For example, my bits and bobs can be put into three basic categories: xeets (short, untitled (title would be redundant since they're already heavily compressed)), articles (stories, essays, lists), and images (I don't rip a lot of audio or video, but I screenshot and save); due to inflexibility, I use a different application for each, which don't necessarily store data in a common place or have high-bandwidth comms channels. However, on atproto, I can embed xeets (bisks) directly in an article:
and articles directly in xeets:
Both of these modes can pull in images easily, as well. Perf is a consideration for self-hosting (I don't self-host so I don't know what's necessary), as is hosting costs, domain acquisition, etc (although if you're a skinflint bastard you can probably wangle a way to do it with free offerings from cloud providers), but really there's only one issue: private data. Because some stuff isn't meant for public consumption.
Coming Real Soon Nowâ„¢