I think part of the reason why Google even decided to make its own phones is because of security. If you read about their BeyondCorp enterprise security architecture, it emphasizes smartphone security quite a bit and how devices without timely updates, for instance, will be banned from the network (Google's own internal network that is).
Given how bad most Android OEMs are at keeping their devices up to date, Google didn't have much of a choice, other than relying on iPhones, too, for its internal security.
I do trust Google to "get security right"[1]. I just don't trust them to secure things I don't want to share with them. Which happens to be a huge percentage of data on and generated by my phone.
[1] In the colloquial sense that people tend to use that phrase.
There is a link albeit not a first order one. If your privacy gets invaded enough, then random third parties will get your data (legally, from google) and then some random hacker will collect it.
I was responding to this: "Given how bad most Android OEMs are at keeping their devices up to date, Google didn't have much of a choice, other than relying on iPhones, too, for its internal security."
My question was why Google would be relying on iPhones when they could just use Nexuses(then) or Pixels(now), since they are pushing their own updates (especially security).