They are big improvements over prior Gen Glocks. Testing by multiple agencies has produced objective data regarding accuracy and mean rounds between failures showing the service sized Gen 5s are the best Glocks yet. The person you quoted is not a Glock fan.
He’s not wrong about Glock marketing though. There is a contingent of rabid Glock fan boys who are equally upset that objective data shows the slim line Glocks are not the equal of the service size Glocks in terms of reliability. Not even close.