> I'm bothered, as I have been since the original iPad introduction 16 years ago, by the unnecessary restrictions placed by corporate powers to run third-party software and operating systems on devices we own.

It's not unnecessary, they do it because they make money as gatekeeper.

There are other reasons.

A big factor in the success of the iPad and maybe just some degree the iPhone, but especially the iPad, is that it’s “unbreakable”. All out restrictions mean it’s computer people don’t worry will suddenly stop working because they clicked to the wrong link. It won’t get a weird virus from their email.

That is a serious upside for a lot of consumers.

Just wanting to be a gatekeeper doesn't cover measures like SIP that don't make them anything and presumably took immense man-hours to implement.

I think the more accurate view would be an intersection of some of the company wanting to make money off gatekeeping and some of the company wanting to make quality devices that stay functional and malware-free even after you give to a deeply gullible grandparent for a while, and the former using the latter as a transparent excuse much of the time.

It's also because U.S. carriers don't like people hooking up arbitrary devices that can run arbitrary software to their network. In the civilized world, you have a device that talks GSM/LTE, you're golden as long as you don't violate any transmission laws. But in the USA carriers are still doing device allowlisting because I guess they want to bin QoS and don't want pro-grade traffic going over consumer accounts, nor the added expense of support for consumer accounts with exotic hardware that "might" break the network.