I just discovered that the Google Home app has some very useful features for my tri-mesh Google Wifi routers. It automatically runs a speed test every other day and logs those results. My Spectrum internet connection runs at 335 Mbps, plus or minus a few Mbps. The image below shows what may be its best feature, being able to individually or as a group, test the speed of all the components between the device and the internet and tell you what the maximum you can achieve is. The choke point between my FireTV Cube and the Internet is the wireless network speed. In other devices, like an under-powered Raspberry Pi, the device was the slow spot.
I don't know about other routers, but if you dig around you might be to find similar tests in your setup.