Yeah Google does have some of the best services. I've used a lot of different calendars, for desktop, cellphone, cloud etc. And no one comes close to creating something that competes to a busy calendar. So I understand how Google having access to how it's users are actually using their software allows them to creates features that we want and great improvements. But yeah more transparency would be nice like, we use X algorithm in Gmail to help Y feature. I don't know, but yeah more information to help us understand what they are doing with it would be nice.
And I agree that Google's security is top notch! No one can accuse them of being lax in that area. And they're not going anywhere anytime soon or in the future so they have longevity as well.