I can buy web hosting for less than a coffee per month that can sling thousands of static HTTP requests per second. In a world where something like Mastodon/GNU Social was the norm, any hobbyist could opt to run one fraction of a grand federated social network out of the goodness of their hearts, for spare change, or for a small fee to their users.

Centralized, siloed social networks are only expensive to run because they're centralized. Things were better when the norm was to start a blog instead of using someone else's walled garden.