>Apple allows you to sideload those kinds of apps using the developer certificate.

A TEMPORARY developer certificate that expires and requires a MacOS system to install.

Meanwhile I can click to download an apk through the browser on my phone, click accept and install. No expiration, no self signed certificates, no other system needed.

A while back I paid Apple $99 for the privilege of compiling an open source emulator and side loading it to my iPad and then having to re-load is after some period of time. It was not worth the effort.

For the average user, it is not even within the ballpark of their abilities.

I would argue that the reason is less form factor and more computational power. The M1 brings best-of-class laptop performance to a tablet, combined with a keyboard and a Linux distro and I would have a much more powerful platform than my current laptop.

You don’t need to pay to develop or sideboard applications to your idevice.

Yes you do, otherwise you are limited to 2 and forced to resign every week, a purposeful limitation that apple has implemented

It's very much not something you could depend on as a component of a serious workflow. You have to stay on top of certificates, and Apple can change those rules at any time.