> Why can’t T-Mobile issue me a free “advertising” eSIM that doesn’t actually provide service (or provides a ridiculously small amount), but allows me to look a

> Why can’t T-Mobile issue me a free “advertising” eSIM that doesn’t actually provide service (or provides a ridiculously small amount), but allows me to look at what reception my existing phone (with all its limitations on bands) would have if I were a t-mobile customer? Why can’t an app that I choose to give location permissions to gather that info, and the Verizon connection info, over time and space and show me a map of where things would be better or worse? This does exist, as other people have mentioned, but it's worth noting that congestion is a big part of what people experience as "reception", and it's not going to be able to show you that. You might have full bars, but still be unable to actually use your phone, because congestion has slowed your 5G speeds down to the kb/s range. This is particularly relevant for MVNOs (such as Mint). Any carrier that's not Verizon, AT&T, and T-Mobile (in the US) is simply renting excess bandwidth from one of those three, and so the actual usable reception is not necessarily going to be well-estimated by the signal that your phone reports.