I'm inclined to say bad luck... My luck is non-existent in this game and has been since early access. Leggos rarely drop, often 1-2 from mystery chests, none from goblins and a handful from whispers.
About 75% of my total playtime has been alongside my partner who gets leggos at a comical rate. He got 4 uniques in 2 hours the other day, and I've had 4 total since we hit WT3.
Blizz just hates us I guess!
Ideally governments should be pushing things like threat to life alerts out via a digital emergency alert system (e.g. Amber alerts) rather than hoping those potentially impacted are checking Twitter.
Which is funny because the UK decided to finally implement this recently and my god the Twitter Boomers were mad.