Comment by charcircuit

And beyond those things there are often performance / battery optimization related things as part of the update too. Just because an app claims it respects your privacy, it doesn't mean that it is a well behaved app.

Most other android app stores enforce a high target sdk. Fdroid is the only one I know that doesn't and allows apps as far back as Android supports. Android has been yearly, except Android 16 it seems, raising the minimum installable target sdk so eventually updates will be needed to run on new devices.