Every western country that has a single payer system as far as I know allows for private clinics, doctors and labs.
I spent 18 years in Canada. The healthcare I got was as good as anything I received in America (in both cases it depends on where you live, unfortunately) and looking ahead to 2026 was cheaper (comparing my tax burden in Ontario to the terrible insurance I can afford for 2026 in America).
Healthcare quality and access varies widely between Canadian provinces. It's common for affluent Canadians to come to the USA as medical tourists and pay out of pocket for elective procedures like MRI scans or joint replacement surgeries due to excessive waiting times at home. There are advantages to the Canadian system but some clear downsides as well.
I spent 18 years in Canada. The healthcare I got was as good as anything I received in America (in both cases it depends on where you live, unfortunately) and looking ahead to 2026 was cheaper (comparing my tax burden in Ontario to the terrible insurance I can afford for 2026 in America).