We have different definitions of an "escape hatch". A user is not an IT specialist. Ordinary people need unobstructed access to lifeboats.

Apple allows developers to self-sign a handful of apps (exclusively from source!) with short-lived certs - it's a complete PITA to maintain a simple app for personal use, and you still need an account. Google is heading in the same direction.

Also features that people assume are part of the OS, like push notifications, but are really a service run by Apple that your phone is locked to using cryptography don't work with self-signed apps.