The problem with the technology is it allows the company, political power, or police to access the data with out user permission, that is a technological problem, belief that just passing the correct laws to resolve this technology problem defy's recorded history and logic
[citation needed] because basically every Google (and Nest) product have used pretty decent protocols since Snowden leaks.
Google and Nest use transport encryption to ensure only the device and google can see the data, but once it stored google can see everything
Zero knowledge data Encryption would require that ONLY the owner of the device has access to the data, not google
and example of this is say BitWarden Password Manager, even though the data is stored on BitWarden Servers, No one at bitwarden as access to any users password vault, The user holds the key, and only the user can view the passwords.
They say there is nothing wrong with the technology, but then go on to list things that are in fact wrong with the not-technology.