Borg backup is gold standard, with Vorta as a very nice GUI on machines that need it. Otherwise, all my other Linux machines are running in proxmox hypervisors and have container/snapshot/vm backups regularly through proxmox backup server to another machine. All the backup data is then replicated regularly, remotely via truenas scale replication tasks.
My biggest concern with SteamDeck was that it would become a 1-2 year upgrade cycle device. I don’t expect the hardware to last 7+ years like normal console lifecycles but I’m very glad to hear they’re being patient and aggressively supporting the software side.