Removing the physical SIM slot, at least for the next iPhone model, is a really bad idea in my opinion. Take, for example, Greece. If you visit Greece and you want a cellular plan that is actually native to Greece, they do not, as far as I can tell from the Internet, issue eSIMs to prepaid customers. Only regular residents with postpaid plans can get issued an eSIM. Now, if you go online, you will find companies claiming to offer eSIM-based plans for Greece, but in reality, none of them are actually native to Greece and will cause your device to operate in roam mode. There is no native Greek eSIM-based plan from any of the country’s providers that a visitor can have issued as far as I can tell.