This is only andectodal cherry-picking, but here's the situation of a few millenials I know...
1) 22 year old, in college, getting his bachelor's degree, but I think he's on the 5-6 year plan (I don't think that many people do it in 4 years anymore). Lives on campus. Has a 2014 Civic that he bought new, is making payments on. Also has a part time office job, but not sure how much he makes. and I forget what he's in school for. I want to say some kind of work that would involve counseling kids? He'll have student debt when he graduates, most likely, but I'm not sure how much.
2) 24 year old, lives at home. Graduated high school, but hasn't gone to college. Parents are getting on him about it. Had a job as a cashier in DC, making $10.50 per hour, which is their minimum wage. Got laid off when the store closed. Just got hired after about 3 months out of work, again making $10.50. Has no car.
3) 30 year old, has an associates degree in Criminal justice or something related like that. Works for a bio-tech company. Makes about $35000 per year. Rents a room in a house, no car. Also has no student debt whatsover.
Just for comparison...when I was 22 years old, I got a job making $10/hr, and had another part time job that paid around $7. That was back in 1992, so it seemed like a lot of money at the time. I was driving a 1968 Dodge Dart, so I was saving money there by not having a car payment, and driving something that was cheap to repair. I was living with my grandmother, and lucked out in that my Dad paid for about half of my college tuition, and I was able to cover the rest.
When I was 24, I had a full-time job and a bachelor's degree. This was 1994. I was only making $10.50/hr, but had benefits. And the other job was up to around $7.50/hr. I was still driving the Dart. Later that year, I was able to buy an $84,000 condo. It was a struggle, and in retrospect I shouldn't have done it, but I survived...
By the time I was 30, in 2000, I was making about $35K per year. Same as my 30 year old buddy, but adjusting for inflation, that would be about $45K today. I was driving a new 2000 Intrepid that I was financing, but it was 0.9%, and had recently refinanced my condo to a cheaper rate. I had also paid down all the debt, roughly $30K, from a bad marriage/divorce that happened between that 24-30 age range. Oh, almost forgot, I also had a second job delivering pizzas. Once the $7.50-8/hr job wasn't enough to cover the mounting debts from that marriage/divorce, I replaced it with a job delivering pizzas, and averaged about $16/hr, after taxes. In 2000, I think it came to around $16,000 for that year. That was also the year I figured I was well off enough financially to give up the second job.
So, looking at me, personally, I was further along financially at 22, 24, and 30 than either of these three millenials are now. But, again, this is just cherry picking, as you can't base the whole generation on these three. There are plenty who are doing much, much better than these three, but also plenty who are doing a lot worse. Just as there are many people who are a lot better off than me, at my age, and many who are worse off.
As for retirement, I'm not so sure it's going to go up as much as people predict. Even though people are living longer, I'm noticing that my parents' generation doesn't seem any healthier at 65-75 than my grandparents' generation did when they got to that age. Well, except for that fact I did have one Granddad who died at 73. He was strong as could be up to 73, but then the doctor discovered lung cancer. They tried to operate, but saw it had spread to the lymph nodes and there was nothing they could do, but slap him back together. The surgery weakened him, and the cancer took off, and he was dead in about 5 months. If he hadn't had the surgery, he might have had a few more good years, but then they could have been followed by many bad ones. So, who knows?