(I make no comment about if the NSA has found other ways into Google or Google has willingly let them in, I do not know the answers to those questions)

Our field is in denial about the importance of diversity to security.

Biologists have no problem understanding this. Why can't we?

Similarly if there are 5 sophisticated attackers after your secrets, some may have cracked your phone security, but not others. If you use more different phone OSes you increase the chance that more attackers have exploits for at least some of your phones.

Also using more phone types complicates training, increases the work you must do checking for vulnerabilities, diluting your efforts.

Better diversity would also mean more choices, which mean some devices are more tailored to needs of a certain type of consumers, like business and government ones. They get less gifs to send, but have their software developed by paranoid people and "do not leak any secrets ever", and "no rce" are their first and only sprint goals.

So basically, now choice is between bad alternative and the even worse one.

Asking for more choices is an important proposition, I'd say

If you have robot armies or something it gets even more dangerous to put all your eggs into one vendor basket.

I can think of: 1. Develop software in the open. 2. Teach security and cryptography widely using openly-developed syllabus. 3. Encourage parallel initiatives.

I don't think you are referring to racial or gender or cultural diversity.

https://en.wikipedia.org/wiki/Defense_in_depth_(computing)

Besides, tens of thousands of separate software companies can easily develop in parallel.

There's only a bottleneck when you assume that this stuff has to come from a BigTech giant. The same mistake people made with PCs and Windows in the 1990s.