Note from 10th June 2020

Nice new #WebPerf tool from @browserstack, it will help show people (aka "clients") not everyone have the same high end device and/or browser.

For example, even on the same Windows 10, Edge 80 is 3 times faster than Edge 18:
https://www.browserstack.com/speedlab/report/bb7303c6b142638557f3cde4415cfea8592a9ae9