I don't think a mega corp having full access to my phone while me not having that is very "secure". Sure it's pretty ok against third parties but in my threat model Google and Apple are also adversaries. Microsoft too by the way.
In my model my Linux pc is a lot more secure as there's no adversary having direct access and more control than me.
Privacy != Security
We shouldn't be happy with the state of security on Linux, while simultaneously enjoying its privacy benefits.
By this definition no operating system Google releases will be secure to you. I think it would be a more productive discussion if you could argue about security ignoring that you have to trust the person who wrote your operating system or designed your cpu.