Understand your enthusiasm but to relate the discussion back to Tim Berners-Lee idea for SOLID data storage protocol... Running self-hosted things like email, NextCloud, Plex, sandstorm.io, etc -- are not relevant to the gp's "nothing changes" complaint.
Without dissecting the SOLID protocol, the basic idea is that transactional data is stored on a separate user-specified "storage pod". It's not just simplistic sharing of "name/address" profile data. Imagining some idealized scenarios might help:
- Spotify music : instead of "playlists, listening history" being stored on Spotify's servers, it is stored on the user's storage pod. Spotify makes API calls to constantly save that data to the user-controlled data location. If the user then cancels Spotify and switches to Apple Music service, Apple can just read the "music playlists data storage pod" and all the recommendations work as expected. No import/export.
- Amazon shopping: instead of order history being in a data silo on Amazon servers. It could be stored in user's "ecommerce orders storage pod". The user can then give permission to Walmart.com to read it to provide product recommendations.
The user "doesn't own their own data" continues with the current AI chat tools. The users' ChatGPT "prompts history" is stored at OpenAI instead of a user-controlled "storage pod".
The walled-garden and data silos don't just restrict consumers. Businesses have the same issue. They use SAP accounting software package or a SaaS tool and their data is locked up in those services. Exports are sometimes possible but cumbersome.
Therefore, self-hosting Plex on local server for a personal music library instead of using Spotify cloud doesn't affect the "nothing changes" narrative. TBL still wants people to have the flexibility/convenience of using cloud services but somehow still keep "ownership of their data".
On the other hand, if you were self-hosting a SOLID Storage Pod at home, and a company like Spotify wrote listening data to it, that's when the narrative changes.
It should be obvious that companies are not incentivized to write transactional data to users' storage pods which explains why the SOLID protocol doesn't seem to gain much traction for the last 9 years.