We bought phones that support eSIM because we do a lot of travelling. Canadian mobile companies charge usurious rates for roaming: $15/day! Times two phones. I can get 2 weeks of data only for Europe for about $11 total on an eSIM. With voice it goes up to about $25. Total.
Initially I didn't see it on the package in the image, so before reading the article it looked like a prank product, just an empty case to hold your eSIM.
Not gonna lie, if this were a real product, I'd be tempted. You see, for Android phones, ESIM registration uses propriety Google code. A programmable device that can present to the phone as a regular SIM would be a boon.
https://jmp.chat/esim-adapter it's realer than you think and it works. Do you have a source to some documentation that says eSIM works only with the proprietary Google code?
Grapheneos people have said so repeatedly in their documentation. At least for the activation part. Once the eSIM is downloaded/installed, it's no longer needed i think.
I'm not the person you're asking, but I have some evidence to support the case that making it work without proprietary code is a problem. GrapheneOS, a privacy-oriented Android-based smartphone OS, write in their usage guide:
By default, GrapheneOS has always shipped with baseline support for eSIM, where users can use any eSIMs installed previously on the device. However, in order to manage and add eSIMs, proprietary Google functionality is needed. This is fully disabled by default.
eSIM support on GrapheneOS doesn't require any dependency on Google Play, and never shares data to Google Play even when installed.
Edit: The fact that they haven't implemented eSIM functionality without using the proprietary Google stuff, indicates to me that it's either impossible/blocked or simply too hard with practically nothing in return to have been prioritised (yet?)
Not so sure that will work. ESIMs are really convenient and cost effective for travelers and people who flit between countries. You can even load up an ESIM before leaving for a country. Your other option is to pay through the nose for roaming. Or arranging a pay as you go SIM in a country where you may not have a full grasp of the language.