Something like Solid is more useful if you want to share data with other people, or use apps that only support cloud storage. There are many such apps (Google Docs for example), but most of them are currently embedded in their respective cloud storage provider. Solid decouples the apps from the storage.
So if you lose your phone, you lose all your data? (asking in a genuine manner)
I have a glacier store of my phone and SD card data that I upload every weekend. I'm good with 5 or so days of phone data loss in that event. (I use a desktop VM that does nothing other than touch Glacier, and my phone, for this.)