Depends what you mean by "steelman". If you take their definition at it's word, then they fail to try all the time, just look at any of their attempts at understanding leftist writing or thought. Of course, it often actually means "entirely rebuild the opposing argument into something different" (because they don't have a basic humanities education or don't want to actually properly read leftist thought) and they can't resist doing that!

Steelmanning is great. We can say whatever we want against them, and when they then get mad we can just go 'well you didn't properly steelman my argument', and have them spin around in circles while we do something important, like chores in the house.