The trends undeniably show that the focus on lifestyle isn't even remotely new or unique. Physicians who don't have the luxury of an easy home life and a career timeline catered towards their physiology (e.g., women) have been fleeing from poor lifestyle specialties for decades. The gender gap in surgery is so high for a reason. The increased focus on lifestyle is, imo, very clearly driven by a much larger percentage of med students who don't fit into the archetype of a physician in the 70s and 80s.
Millennials don't think about their careers at all similarly to Boomers because they mostly don't have that luxury.
In the 80s a young doctor was most often an upper middle class white man with a homemaker wife. They started med school at 22, finished at 26, and largely just became attendings after residency. Once married, their partners were often happy to stay home and take care of domestic duties, so life at home was easier. Taking care of the kids meant food on the table and sending them out into the neighborhood. It's not a surprise that a workforce that looks like that is more willing to grind 90 hours/week in residency and more hours as an attending.
A doctor today is a man or woman who starts at 24-25 after several gap years to compete in the CV arms race. Then they spend 4-5 years in med school, often taking a research year or doing an additional degree. Then after residency many are pushed into 1-2 year fellowships that didn't even exist in the 80s as job markets get a bit tighter for many specialties or work environments. So this 28-29 year old soon-to-be intern has a working spouse/partner, is probably planning on kids during residency (and kids are now a much larger expected time commitment than in the 80s), and knows that there may be further hoops to jump through even after residency. They're not coming home to a clean house and made dinner knowing their kids are off playing in a nearby park. They're rushing home to pick up kids from their 2x/week fencing lessons and meeting their working spouse with a car full of groceries so they can start cooking dinner.
It's not at all shocking that the life of the physician who lives at the hospital and makes bank is no longer the ideal for most med students.