Why has Apple made it so difficult to change one's country in iTunes or App store ?

This article describes how to change your country setting and the requirements and results of doing this:

Read how to "Change your Apple ID country or region" click here --> https://support.apple.com/HT201389

"Redownload your apps, music, movies, TV shows, and books on any devices that you might use to play or read them in the future. That's because some types of content might not be available in your new country or region. (Learn what types of content and services are available in your new country or region. - https://support.apple.com/HT20441 )"

"To make sure that you can access your previous purchases in your new country or region, redownload your previous purchases on every device on which you might want to view the purchase before you change your country or region."

The requirements for changing countries has been like this for as long as I can remember.

I don't work for Apple, I just know what they say in their documentation. The sections below are copied from the USA Apple Media Services Terms and Conditions document but I suspect they are very similar for all versions of this document --> https://www.apple.com/legal/internet-services/itunes/us/terms.html - Last Updated: September 16, 2020

"Our Services are available for your use in your country of residence (“Home Country”). By creating an account for use of the Services in a particular country or territory you are specifying it as your Home Country."

"Terms found in this Agreement that relate to Services, Content types, features or functionality not available in your Home Country are not applicable to you unless and until they become available to you. To see the Content types available to you in your Home Country, go to the Services or visit https://support.apple.com/en-us/HT204411. Certain Services and Content available to you in your Home Country may not be available to you when traveling outside of your Home Country."

Media and app licensing and distribution vary from country to country and are also up to the owners. As you can see, what you can get access to is determined by your residency. A very tiny monority of people claim dual residency but unless you can demonstrate this by the requirements then you are restricted to the country's store for which you can prove residency. Even then you'd have to change country settings which can be a buisance, or use two Apple IDs which can also be a nuisance.

Yes, it is a nuisance Apple changed app downloading several years ago. Supposedly this is because instead of an app being "universal" they changed distribution to machine-specific versions. You used to be able to download an app on your iPod and then copy it to an iPad. That's no longer the case. You have to download the iPad version from Apple.

As for iOS updating, I know you won't like it but I for one don't update OS until I know the consequences and you may decide to not update OS if this is the only way you can keep your old versions working.