In Europe contactless payment is nearly everywhere - nearly every store supports it. Even in Germany (which is historically very pro-cash), since Covid more and more people pay with card and many of whom pay contactless.
In the EU we have some rules that even contactless payments with card sometimes, but not always, need to have some kind of additional authentication in the form of entering your PIN. Contactless payment methods via phone or watch don't have this need because they already have their own authentication methods. That's why so many people pay with their phone or watch. Its just more convenient and always contactless. (no PIN needed)
How is it in the US? Are things like Apple Pay still limited to certain stores?
I cannot directly answer your question, because I am looking into this topic myself currently, but I found this HN discussion from two weeks ago, which should give you more insights about pi: https://news.ycombinator.com/item?id=46844822
You could argue the same with Boeing vs. Airbus. Why should Europeans build their own aircrafts? Today I think a lot of people are happy, that Airbus exists to compensate for the problems that Boeing has. Competition is good and will lead to better solutions in the long run.