GP sessions being around 20 minutes is pretty standard in North American and European countries. You can't have standard hour-long GP sessions, as it'd become impossible to make a timely appointment, no matter which system.
Ever wonder why famous people and celbrities always seem so healthy? They have unfettered access to well paid doctors. People with lots of money can spend literal days with GPs, constantly trying and testing things based on feedback loops with the same doctor at the same time.
When people are forced to have a consultation, diagnosis, and treatment in 20 minutes, things are rushed and missed. Amazing things happen when trained doctors can spend unlimited time with a patient.
Can confirm having experienced both the USA and Dutch systems now. In both countries is my visit only about 20 minutes + another 15-30 sitting in the lobby because they doctor is always running behind schedule.
In theory, the Dutch system will take care of your more quickly for "real" emergencies as their "urgent care" (spoedpost) is heavily gate kept and you can only walk in to a hospital if you're in the middle of a crisis. I tried to walk into the ER once because I needed an inhaler and they told me to call the call the hotline for the urgent care... this was a couple of months after I moved.
That said, I much prefer paying €1800/year in premiums with a €450 deductible compared to the absolute shitshow that is healthcare in the USA. Now that I've figured out how to operate within the system, it's not so bad. But when you're in the middle of a health crisis, it can be very disorienting to try and figure out how it all works.