I can confirm that in multiple European countries you just walk to your GP's office and wait an hour or two (worst case) if you do not have an appointment.
I waited 20 min last time I went without appointment.
Specialists is a different story, the worst being psychologists/therapists (wait time counted in years where I live).
The equivalent is urgent care clinics in the US. They are everywhere and you can be seen in 15-20 mins, covered by employer medical plan. Testing, imaging, common medicines and treatments on site.
Wait for specialists and surgeries are significantly less in the US than all other G20 countries.
I waited 20 min last time I went without appointment.
Specialists is a different story, the worst being psychologists/therapists (wait time counted in years where I live).