I used to believe that was true, but recently I read that even in the hardware space formal methods have limited application - like software, they're usually us

I used to believe that was true, but recently I read that even in the hardware space formal methods have limited application - like software, they're usually used only on very specific sub-parts like MESI protocols. But it's not the case that a modern CPU is extensively applying formal methods. W.R.T. things like static type systems, I agree. But progress there has been fairly minimal in the widely adopted languages. Mostly, in fact, the type systems did not get stronger, but the focus was on making them easier to use through more type inference.