> There is nothing stopping Apple from making the same device, but giving you the keys to install your own software on it.
They do, at the app level. As a developer you can install whatever app you want on your own devices, even apps which would never be allowed in AppStore or TestFlight (although still not with all the entitlements Apple’s own apps can get.)
Even then - apps which might want to do things like send multicast packets (very useful in lots of home automations situations) can't do it, using the developer program, without going through approval on the store.
You utterly do not own those devices. Apple sells a house where they kept the keys to all the locks, but people think it's ok "because they'll keep me safe and unlock my doors when I need them to!".
Nevermind the risk is mostly a marketing boogeyman in the first place.
You can do this only if you pay Apple $99 / year and deanonymize yourself with billing details. If not, you have to reinstall weekly, losing your local data.
They do, at the app level. As a developer you can install whatever app you want on your own devices, even apps which would never be allowed in AppStore or TestFlight (although still not with all the entitlements Apple’s own apps can get.)
OS level, your point stands.