So, "Passive" Perception now actually has a "passive" component...
This is horrible.
The terminology before was the horrible part. It was a routine or hidden check mechanic--perfectly fine, just a bad name--should have been "Repeated or Secret checks" or something.
Now, the name is appropriate, but the mechanic sucks: IT SHOULD NOT BE 10 + modifiers!
Using 10 for base is just wrong IMO. 10 is the "average" for making many checks (the routine use) or the default if you are trying but the DM wants it secret (another prior use).
If you aren't actively trying to do it (the current more accurate use of "passive"), it should be base 5.
With a base 10, 45% of the time the PC does worse WHEN TRYING to notice something than when they simply happen to notice it without conscisouly trying.
Something like Reliable Talent gives a base 10, for example, should demonstrate how using 10 for passive perception is simply wrong.