History seems to repeat itself. This reminds me of the times when a company was the ONLY one competing with Windows. All other companies were already on the windows boat or have plans in place to go follow that route. That company was Sun.
Now it looks like the ONLY company that stands against (read competes with)Chromium is Mozilla. You have to pick a side
That's not the point.
Of course that the software will have the same number of bugs/vulnerabilities on OpenBSD.
The question is how much damage an exploit/crash will do overall. OpenBSD has quite a few of protection mechanisms in place.