Source? The only implementation I know of is on iOS, which allows you to transfer esims between phones that are on the same icloud account. For every other phone the solution was to get a new QR code from the provider.
But I agree that this is exclusively a policy problem, not a technical problem with eSIM, which clearly supports reusable profiles as well.
I do agree that cell protocols in general need to be reformed to get rid of static device identifiers like IMEI. I'd go even further and say that the tamper proof aspect of SIMs should be eliminated - the application processor can store the key to auth to the network, putting the user in control rather than suffering arbitrary top-down restrictions enforced by hardware they purportedly own. Though obviously that's a pipe dream while regulators continue to work for Ma Bell.