I didn't mention hand-written letters at all so I've no idea why you're asking that question.

Your original message seemed to express concern that the original purpose of the rules for international shipping was to support people in poorer countries?

If this cross-subsidisation is removed, then people in poorer countries will pay more and people in richer countries will pay less to send stuff to each other. That's simple arithmetic.

And I was wondering how someone could simultaneously support such a policy while expressing concern about access to international post in poorer countries.