I like the new version, Page Speed Insights actually measures page speed now. I used to get horrible scores even though pages were fully loaded in 1/3 of a second. Now I get perfect scores.
I have clients that made a big deal about PSI and did all sorts of things to raise their old scores. Then the system changed and they went from scores in the 90s to scores in the 30s.
The new system tends to brutally punish things like ads, even Google's own AdSense. Slow servers, bloated HTML/JS/CSS, all those things that make browsing painful get penalized in a much more fair way than before.
I agree, the old tool had many issues, and I think for the "synthetic" portion, moving over to Lighthouse (used in the browser, headless chrome) makes sense.
But, the sudden move from basing ranks off median vs to the 90th percentile, needs to be considered. (Or at least some function on outliers should be applied perhaps weighted by pageHits).
From my initial querying of CRuX and using the tool directly — it tends to punish highly trafficked sites, making it seem like they are "slower"...when they are often highly optimized.
As someone who make the mistake of being obsessed with the Pagespeed Insights score. Was kinda like a Monty Python sketch to make all the adjustment need it on my code and server to get something >90... to then later get that score down thanks to Google analytics and another Google Scripts.
My advice. If your site it's over 70 you're probably good.
I wrote some of the updated documentation when PSI migrated to Lighthouse. I'll forward your question to the team. You can also try forwarding this question to the Chrome User Experience Report mailing list [1], because that's where this data is coming from.
PSI has been a pain in the ass from the day it was released. I can happily ignore it, but my customers don’t.