I just checked on my personal iPhone (iPhone 13 mini ftw!) and Developer Mode is right there under Settings > Privacy & Security > Developer Mode. My phone is a production device running 17.5.1 that’s never seen a beta release of iOS.
I’m not sure why it’s failing in your environment. Is your device enrolled into an enterprise’s management system? It’s possible that it’s preventing you from accessing Development Mode.
Share and Enjoy
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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"