@thibaultamartin @postmarketOS @gnome i think many old devices could be repurposed for specific simple uses, as long as file synchronization and local-first apps run on them. I reuse old android tablets as e.g. 1) recipe viewer in the kitchen, 2) jukebox in the living room, 3) picture frame (running slideshow).
The challenge for me is how to keep file libraries on old devices updated when synchronization apps like @nextcloud eventually drop support when the OS pass <0.5% use rate..