People with non-rooted phones won’t get automatic updates via F-Droid which is a big hurdle.

Not true if the app to update targets a high enough API version (I think API 34 or 35) and if you use F-Droid Basic.

NOTE: The Basic version of F-Droid Client has a reduced feature set (e.g. no nearby share and no panic feature). It targets Android 13 and can do unattended updates without privileged extension or root.