Why do Duchess’s in random matchmaking never use their ultimate art?

Over 200 hours played and it’s pretty consistent that it happens. Do they think it doesn’t do damage = useless?

There have been multiple times when it’s just the Duchess being alive against the NIGHTLORD and they never use their ult to save party members when they’ve never used their ult in the entire run thus far.

I’ve played games with 2 Duchess and the entire run they never used their ultimate art? JUST WHYY.