what they basically say is that (and this is only valid for people using tor or mullvad browser with stock settings) if everyone has the same fingerprint, and if you dont sign in to anything else, they basically look same to the websites, so you dont have to use some privacy frontend, it is ot adding in any benefit. However, these conditions deffenitely are not that easy to meet for day to day use.

on my first read, i definitely got that some guy bill is proposing