As an OpenBSD lover and frequent user I will tell you it does not support but a significant fraction of the hardware Linux does, and has many features that are reduced in functionality or just gone compared to Linux.

Is it bulletproof? Definitely! But you need the genius of Albert Einstein as well as the patience of Mother Theresa to actually use it in production.

Is anyone spending millions of dollars on checking OpenBSD?

But it also got its share of use-after-free and OOB access vulnerabilities this year: https://feedly.com/cve/vendors/openbsd

> Funny how OpenBSD is "memory-unsafe" yet doesn't have these issues.

First of all... Do you really believe that to be true?