The recently release 1.16.1 supports the first beta of untrusted nodes, aka nodes that will sync data but don't know what it is, as it is encrypted with a passphrase you set.

so drop off an old machine at your parents / buddies / exs house, give it internet connection and cron some updates + reboots + power on after an outage and boom, if your house and all your devices burn down, you can get your files via decrypting with that password you saved to your email / password manager.

I love Syncthing and it's replaced Dropbox and Microsoft 365 for me. ok i keep the latter for online dictation when I'm not near a pc with dragon installed on it, but still, I don't need to trust MS with my data in their cloud.