I'd love to see some other data. But afaik it's basically not contested that the US has shorter wait times than the UK and Canada

I agree with the main point. The thing is, in the US, wait times are a function of how much you're willing to spend. You can always pay for priority. But most people won't pay more, and the reality is that most healthcare systems have far less provider supply than demand, particularly in dense urban areas where most people live.