Earlier quoted context omitted.
There's always somebody with root access to the servers.
Encryption with customer managed keys solves that pretty easily. It also solves any ethical questions with regards to furnishing data to comply with warrants. This creates a new problem of managing keys, of course, but that's been solved many times now in other parts of the industry.
However, worse, features that use AI to detect movement/people/etc can't be implemented without access to the underlying video stream. The only remotely viable way would be via homomorphic encryption, which has serious limitations still.
It's far easier to do what they did, and just limit root access to a very small number of trusted people.