[kalleboo]

Part of that is kind of what Apple has been going for the past couple of years with macOS, even though they haven't gone all onboard by removing the hierarchical part (since there is so much legacy software and users would revolt).

A new user profile will come with a prominent "All my files" live search shortcut that just shows all your files in a jumble sorted by when you last used them. Then they expect you to search and filter through them by metadata (which is automatically extracted/indexed by Spotlight). Then you can save these searches/filters as saved searches which are live-updating virtual folders.