[bookwormAT]

most of the time google collects data it is because users want this data to be collected.

If Google would not store emails on their servers, people would leave Gmail and go to a service that does. If Google would store emails, but end-to-end encrypt it, people would leave gmail and put their data to a service with a working spam filter.

Google Now is very popular and a reason why people use Google services.

For Googles revenue it is far more important that people use their services (and therefore watch ads), then it is to create "better ads". I say that because nobody seems to get "smart ads" that are actually interesting to them. Googles gmail ads are little more than "if word is used in conversation, show product related to word".