I'm not sure why you would have to remember IP addresses. We routinely "dial" telephone numbers by selecting from a list of contacts. IP addresses are approximately the same length as telephone numbers. The folk wisdom is that people can remember about 7 digits. But even if you disagree on all of this, what does that have to do with letting someone else control our email? The issue here is control, not whether we use names or numbers or something else when we enter the address of the recipient.

The nonportability of IP addresses is a problem in its own right, but I don't see the relevance here. Again, you are trying to engage me in a debate over domain names versus IP numbers. Perhaps that is an interesting issue, but here I am interested only in the issue of control over email (and because email and DNS have been coupled together, DNS). And that is what the OP is interested in as well.

I said that email and DNS are closely linked and this makes email more challenging for any user to control. 1. Because it complicates the setup and 2. because DNS as we currently accept it is controlled by third parties.

You are trying to suggest that I am advocating against having email addresses that use names instead of numbers. I am not.

If email is linked to DNS, and someone else controls DNS, then you cannot control email.

If you disagree with the preceding statement then please explain.