eSIM always seemed like step backwards.
Going from phone to phone was always a huge pain in the ass with CDMA carriers like Verizon and Sprint (and all their MVNOs). Any time I'd upgrade or switch devices I'd have to call a 1-800 number, wait on hold, and deal with someone transferring the account from one device to another.
This was a headache that sometimes took
hours to fully complete (voice mail would usually lag).
With GSM carriers like AT&T and T-Mobile (and all their MVNOs), switching devices was as simple as pulling a SIM card and popping it in the new device.
This was a simple process that could take just a matter of
seconds to do.
If you have multiple devices, wanted to switch back and forth between Android and iOS, traveled, or whatever reason you had, having a physical SIM made things simple and easy.
With eSIM, someone basically said "remember all the headache people had when
their account was tied to hardware? LET'S GO BACK TO THAT!"
eSIM, so simple Apple had to publish multiple document to try and help people figure it out:
Learn what an eSIM is, how to set up an eSIM on your iPhone, and how to transfer a physical SIM to an eSIM.
support.apple.com
Set up and use Dual SIM.
support.apple.com
What to move your account from one phone to another?
* the phone must be operative
* the phone must be up to date
* the phone must be connected
* the old phone must be physically near the new phone
If any of these conditions aren't met (the phone is broke, you lost/sold it, etc), you're back to the "call your carrier's 1-800 number and be prepared to sit on hold" like the old days.
I'm sure there are multiple benefits to eSIM, but *I* personally have not seen anything that would make me want to switch to it or give up the freedom of my old SIM card.