I think it might be more than just having things relatively easy. Most of the boomer generation were poor and miserable. Maybe less miserable than modern people, but they had shitty medicine that didn't work, alcoholism like you wouldn't believe, shitty sex, universal smoking, the lead, and a bunch of other stuff.

And I've noticed a lot of the ones who actually made it in to the 1-3% of the population that could be legitimately called middle class spent their whole lives chasing a "good career" and money and shit, and now they're old and all they have is money. No purpose, no meaningful accomplishments. They never even tried to change anything and a lot of them never even considered changing things. They just did what they were told and now they're at the end of their lives, looking back on decades of work that often made the world actively worse, their kids hate them, the world has changed incomprehensibly. Sure, they've got food and medicine, but those higher tiers of Maslow's pyramid are completely empty.