Maybe in somewhere free like the EU or SEA. In the US, most phones bought from a carrier (and most sales are that way, some exclusively so) are locked so that no other SIM (e or physical) can be used.
That’s your problem as a consumer accepting that. This thread makes me depressed, with the amount of people happy to allow shitty US consumer hostile practices to become more common globally.
as a consumer accepting that
That’s the special condition we get in the US, though - there is little or no effective choice across the spectrum. Without regulation, corporations will become asymptotic to maximum financial extraction techniques. There are few real choices at the consumer level and the barriers to entry are such that a single consumer - or even an uncoordinated (read: without a national, staffed organization) - cannot circumvent the system.
Cell phone use was a US thing that spread there before any other country. Five fold the amount of mobile phone users than the next closest country. They were also invented in the US.
The way of buying a cell phone and paying too much for the monthly pan, but getting the phone for free kicked off in the 90s and has never managed to go away because yeah, the cell companies are assholes, but also because consumers got used to getting phones this way. The bs part is that you plan isn’t any cheaper, even if you own your phone outright.
But for most people in the US there’s little use for switching carriers while using your same phone, so sim stuff isn’t all that important. Most don’t vacation outside of the country.