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

kiwi

that is what they are doing - guessing

i may be wrong here, but if i remember correctly, in ech, essentially our first communication is done with some central server (which as of now is mostly cloudflare) and then they make some connection with target server, and then a channel is established between us and target. my google-fu brought me this , which is basically this only

https://cf-assets.www.cloudflare.com/zkvhlag99gkb/3C9ceBTx5AQXu8tS0lgzdF/55ea89f5a56843db15296b2b47f7b1c2/image3-17.png (https://blog.cloudflare.com/encrypted-client-hello/)

I am unfamiliar with QUIC, and quick search basically tells it is kinda like multilane highway for udp.

If I have to compare, (not a network engineer or a person who has studied networking, to me anything beyond the simple protocols seems magic), QUIC seems like a techt which is only used after you have made connection with target, so its implementation is google independent (they seem to be lead developers for this). Whereas in ECH, cloudflare are the primary devs, but also the holder for the public keys (someone else can also be the holder, but i dont know of any other provider currently, maybe my lack of knowledge here)

Essentially just an extension of your point that implementation is lacking

for me, currently the problem is over reliance on Cloudflare, which is yet another big tech company