Yes, as you say aspirational. Getting everyone to adopt something is that hardest part. In the end there will always be some that dont adopt it or adopt something else, and the wider web will still break inbound links. We tried this with crosscloud at MIT which was the parent project of Solid. Basically solid with portability. They had aspirational portability goals, but these things are kludges that dont get broadly implemented. One reason I was keen to separate solid and crosscloud. Crosscloud ended up dying, and solid is still going with the federated model. There will be an intersection where users have bridges (we're using one now, yay!) and some opt-in hybrid workarounds, but another thing that doesnt help is that there's multiple different valid approahces. I get that the video is aspriational, but over promising stuff does niggle me a bit, in what is otherwise an excellent explanation.