You can't run unsigned apps on an iPhone. No, not even your own.
You can't generate a certificate for an iPhone app longer than one week, and even then, the certificate you generate only lets you run code on an iPhone physically connected to the computer where the certificate was generated.
EVERY OTHER way to get a certificate, including for internal development and testing through testflight, requires the app to go through review. Every. Single. One.
It's not simply for putting the app on the app store, it's for running the app at all.
Enterprise certificates were supposed to be a way for a company to avoid shipping their internal tools to Apple, but they turn out to be a way to actually run useful code on an iPhone, even if it's not something Apple wants you to do.
Only if you do not have a paid developer account will the app be uninstalled after 7 days. Otherwise the app can stay installed for as long as your account is paid up.
And the phone does not have to be physically connected for it to run.
This more than anything else Apple does, shows quite clearly that you do not own your iPhone, you are paying Apple to be allowed to use it. So you want to run your own program, with no interest in publishing to the App Store or sharing it with others? Sure thing, just pay us $100 a year...
I mean, I know there have been recent changes in apple's attitude towards enterprise certs, but I've been able to sign internal ad-hoc apps with a developer cert which would last one year (i.e until the provisioning profile expires) with no review.
Granted, you need the unique identifier of the device and it limits you to a certain number per year (100 or 200?), but this still seems different to the situation you are describing.
Fairly sure I did this last year, even. Though admittedly we switched to android at some point, purely because it was too much headache.
> EVERY OTHER way to get a certificate, including for internal development and testing through testflight, requires the app to go through review. Every. Single. One.
Not true.
There is still Ad Hoc distribution, where you can sign the app to run on any device in your developer account (up to 100 iPhones + 100 iPads) and host it for download yourself. The build runs until your developer cert expires (1 year IIRC?)
I believe this is how TestFlight worked before Apple bought them
EVERY OTHER way to get a certificate, including for internal development and testing through testflight, requires the app to go through review. Every. Single. One.
It's not simply for putting the app on the app store, it's for running the app at all.
Enterprise certificates were supposed to be a way for a company to avoid shipping their internal tools to Apple, but they turn out to be a way to actually run useful code on an iPhone, even if it's not something Apple wants you to do.