For reference, this was in Japan. From my experience, there weren’t SIM card vendors until you get through customs. That could be a 2 hour long process from landing to entering the country before you can get a SIM and communicate with family or your travel arrangements at your destination. It also won’t be doing you any favors if you need to pull up documentation on your phone to provide to the customs agent, like your return ticket.

I can buy an eSIM and install it before leaving my home and verify it works instantly. It’s just a better experience than the alternative.

also who waits for sim cards in the mail instead of just buying one?

Cellphone carriers that have no brick and mortar? But are also significantly cheaper for basically the same service

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.