Only recently, I discovered its actual reputation is to pack a punch.
I grew up with Thai chillies as to mean “the chilli”. I still put this stuff on anything that needs some chillies. And that really does pack a punch.
It's just that they used to be spicier.
But if you wanted something really spicy, you never bought jalapeños even in the past -- you went for serranos or habaneros if you could find them.
In French, we have a (generic, as in encompassing the whole family of plants) word specifically designating all members of the capsicum family that are spicy: Piments, so as to exclude Bell Peppers (which we call Poivron) from any conversation about this stuff.
Bell Peppers can be considered a main ingredient and focus (in weight) in a recipe, while the others are only ever used as spices.