When you measure the speed of your Internet connection you should always use a computer that is connected to the network with a network cable and not through wifi.

And never use a speedtest page in the browser but the Ookla Speedtest app from the Microsoft store.

First of all, I guess most people can't use that speed. Unless you have a special case. But i do agree it's fancy and if you pay for it you want to see it. 

It's not clear from your picture whether the machine (or mobile equipment) you used to measure the speed is connected to the network via WiFi or "ethernet cable". If it's WiFi they are excellent speed metrics

The best thing to do is to check the speed when the people come to install it. They got instruments to check. 

If you are connected via Ethernet cable to the "router" from kpn and still not showing at least around 900 then check with KPN. But first try another laptop and cable. 

That is absolutely clear, almost all measurements in that screenshot are done through wifi and one through 5G. (See column type.)