@ItsThatDeafGuy 👋 notes that "free" is largely part of the past, and I think there's some truth in that:
It could mean users paya huge central host to keep it afloat as it tries to manage bajillions of users uploading umptygazillion media files, and any failure gets felt by all users.
Or it could be that more folks obtain their own domain, set up their own $5/month VPS, and run their own instances independent of the problems at the central site. Maybe they avail those services to friends/family allowing free participation for some folks.
But the AP model scales fairly nicely as the decentralization grows as @WiteWulf opens with.