But I don’t need to do any of that either. My phone’s settings have a transfer option for eSIMs and it passes the eSIM data to another phone.

No need to interact with the carrier app, no need to interact with the internet, no need to login to anything.

I guess activation times could be a thing but mine is always immediately active so I never noticed it.

So that leads me to my previously stated conclusion: eSIM isn’t the issue, carrier implementation is.