The type of person to rock Calibre would probably have airplane mode on constantly. Mine’s been that way and I still have epubs sideloaded on my Kindle from when I first got mine all those years ago.

It’s not confirmed. Its just pessimism, albeit very well argued and precedented.

Everything except the Mac line has a locked boot process. So your iPhone or iPad must run the latest iOS, must have an Apple ID, must source apps from Apple, and Apple has gotten so good at securing their devices that its basically killed hobbyist jailbreaking.

Anything you do on these multi thousand dollar devices is only because Apple allows you to— reluctantly, I might add.