i read that as "why bother with a hacked up chromium when i can just use firefox"
"Reflections on Trusting Trust": https://www.cs.cmu.edu/~rdriley/487/papers/Thompson_1984_Ref...
And even if you go Full OpenBSD, you're still relying on some chip microcode and BIOS that you bought sight-unseen.
So, unless the Free Software Foundation staffs its own fab staffed by angels, the best we can do is minimize risk.