Perhaps, but Apple would still have an edge on tight integration with the OS resulting in a quick and frictionless user experience. If that wouldn't cut it for some developers, so they would bother themselves building a separate processing, well, then Apple would probably have to lower their fees.
Personally for me, as a developer of applications, I could care less about 30% fee. I find it reasonable. What I DO care about is restrictions on owning the device and users' inability to run any app they need - even if it is not vetted by Apple. In part it is because I happen to live in an authoritarian country which government loves to block apps in the AppStore.
Anyone can get a developer license and run whatever stupid apps they want. That seems like sufficient opt-in that you are likely competent to assess the risk of the apps you're installing.
So you are suggesting users in China apply for a developer license and build their own build of Signal and Protonmail apps? Really?
And how would said users receive push notifications for their apps from Signal?
UPD: oh boy, and I forgot to mention that such users would also have to buy Macs - you can't build a 'stupid app' for iOS without XCode, which runs only on Macs that support the latest version of macOS.
What makes you think I'm suggesting that? I was simply ridiculing the idea of forcing users to acquire developers license.
The right way, of course, is to allow third party appstores and app sideloading. Just like we have it on macOS - and it doesn't look like someone was made unhappy because he can run Steam and buy Sketch directly from the developer.
Not forcing people to be a developer to sideload apps isn't addressing the elephant in the room that you need to have a Mac ($800+) to build them. Your solution would best be 'allow downloading and installing .app packages from websites'.
I don't quite understand why you are addressing this to me. I believe I was quite clearly against forcing users to build apps and to allow them installing apps from everywhere.
Personally for me, as a developer of applications, I could care less about 30% fee. I find it reasonable. What I DO care about is restrictions on owning the device and users' inability to run any app they need - even if it is not vetted by Apple. In part it is because I happen to live in an authoritarian country which government loves to block apps in the AppStore.