The data (in solid for example) isn't local - it's just controlled by the user. The key point is that the user's data is decoupled from your service - it's not

The data (in solid for example) isn't local - it's just controlled by the user. The key point is that the user's data is decoupled from your service - it's not necessarily decentralised. Backups are handled (by the user) - the user can purchase cloud storage through a provider (like https://inrupt.com/products/enterprise-solid-server/ https://inrupt.com/products/enterprise-solid-server/, though there are other free services - or you can host your own wherever you want). Users don't have to safely handle cryptographic keys or deal with device syncing.