So for the Network it does that based on the RTT in CrUX. You can see in this video for bbc it flips between Fast 3G (~60 ms RTT) as recommendation for Desktop and Slow 4G (150ms) as recommendation for Mobile and those are based off of the RTT data in CrUX (checko ut CrUX Vis to see that).
1 likes 1 replies
?