>But in recent years, nearly every modern phone shipped today has an eSIM
How many phones other than iPhone, Pixel, and (very recent) Galaxy S/Z have eSIM? There aren't that many cellular IoT boards that support swappable eSIM either (some boards say eSIM, but what they mean is that the IoT vendor's SIM is soldered onto the board - thus "embedded SIM"- not that you're allowed to load eSIM of your choice).
How many phones other than iPhone, Pixel, and (very recent) Galaxy S/Z have eSIM? There aren't that many cellular IoT boards that support swappable eSIM either (some boards say eSIM, but what they mean is that the IoT vendor's SIM is soldered onto the board - thus "embedded SIM"- not that you're allowed to load eSIM of your choice).