My issue with the entire discussion, and lots of the community is that formal methods are not all the same.
Some are expensive, yes. If you insist on doing them all, you'll never finish anything. But that's not a reason to dump the entire set.
Im sure if somebody wrote a blog post that provided a sensemaking framework for WHEN formal methods are appropriate vs waste your time it would be popular.
I see hints of this all over the thread - e.g. some people seem to believe it works well for state machines (though I suspect they were nontrivial ones), but as a topic it rarely ever seems to be addressed head on. OP certainly doesnt.
I suspect this trope will reiterate again next year with "formal methods! useful! sometimes!". The community has been like this for decades.