Comment by GuB-42

And yet, according to the author, it has some quirks.

The idea is that the font itself is not particularly serious, but we are used to see it in serious contexts, so we make the association.

And there is also the support, when some text is engraved on metal, there is some permanence to it, some commitment. The one who wrote this really means it. It is not like a sheet of paper, or worse, a computer screen where everything can vanish at the push of a button.

I think the titles summarizes it perfectly. It means hard work. When we see this, we imagine industrial machinery and professionals, because that's where it is used. In an alternative world where Comic Sans would be used for this purpose, it would be seen as serious.