I think there is a bit of a clear gap between those who "got in" before things were too expensive, I don't think that gap in anywhere so clear as "born in late 80s" or anything so blanket-approach, when applied to the whole country. To me the biggest determiners of being able to get in are:
1: Location. Young people / lower earners may have been priced out in Vancouver 15 years ago and Toronto 10 years ago, but other cities are still affordable (if getting less so). I find the discussion tends to get skewed towards the more unaffordable places since, well, they're unaffordable, and lots of people live there. But I still see statements along the line of "all 20-somethings have missed the boat" and I just don't see that in my world yet.
2. Single vs couple. Being able to afford ~twice as much, plus the stability of only going down to one income rather than zero (unlikely that both lose a job at the same time). It may drive towards a larger purchase, or require other compromises, but double the buying power is hard to beat any other way.
3. Family setup. The egregious example is gifting hundreds of thousands of dollars to buy, but there are MANY ways in which the parents' situation, and how much they extended that to the kids, can have a huge impact. Whether it's paying or helping with school, letting kids live at home during/post school, providing a car so a kid can take a better job further away. Things that don't even have direct value, like mindset towards money/property and education towards money/property. This one is huge, but still, all the help in the world still doesn't mean guaranteed success.
4. Income. More money is more money. This can be tied to career choices, career progression, effects of student debt, different stages of life (still figuring things out vs on a clear path), demand for your field, willingness to move vs stay close to home or family.
A look at me and my three siblings illustrates some of this. We all had the same upbringing, and the same help available to us, but different ages and life choices have us in very different situations. Two of us have "got in", I'm not sure how likely it is for the other two any time soon.
1. Me, 28, estimator. College 3 years, lived at home 3 years. I had school debt, but paid it off in 6 months. Saved but not aggressively, and spent a lot too (new car). Moved in with girlfriend, who had no school or car debt (parents), both of us had immediately gotten jobs in our fields out of school (construction mgmt. and HR). Apartment for a year and a half, then in 2018 bought a house in Hamilton for $350k. This was well below what we were approved for and is very comfortable for us to afford.
2. Brother 1, 26. Cabinetmaker apprenticeship 3 years, working most of that time and collecting EI during the in-school portions. No debt generated, in fact saved a bunch, lived at home the whole time. Doesn't spend on anything, bought a used truck for cash. Left to Sudbury for GF's school, moved in with me when that didn't work out, fully employed in both cities. Bought a house by himself in 2020 in Brantford for $350k. This was the absolute max he could spend, and required a higher down payment than I did, and his budget is very tight without Brother 2 moving in.
3. Brother 2, 23. College 2 years, moved back home for 1 year. Social work, but didn't go into that field, and works at an auto parts factory. Moved in with Brother 1 when he bought the Brantford house. Not sure on debt/spending with him, but he doesn't do much besides gaming, paid cash for a decent used sedan. Assume he's saving decently for his non-minimum-but-not-stellar wage.
4. Sister, 21. College 2 years, didn't want to go into that field, 1 year training course in something else. Still isn't sure what she wants, lives at home and works at Tim Hortons. Drives one of mom and dad's cars. I don't think she spends much either - they live in the country and there hasn't been much to do for the last little while for some reason.
Like I said, very different for different reasons. No cash gifted but the opportunity to live at home and save - parents don't charge rent but help with hobby farm chores is expected. By far the biggest differentiator has been the fact that I have a second person. If brother 2 and I were flipped in age, he likely could have bought "more/better house", but since he's budgeted quite tight, maybe would not have.
You could look at that example and think that the $350k affordability line had moved from Hamilton to Brantford, but it's not that clear-cut. Brother 1 🞵🞵🞵🞵🞵🞵🞵 hates living in the city, and also works in Cambridge. More money would have gone towards getting out of urbanity, not further in.
Other than more time to save a down payment, Brother 2 and Sister could be much closer to buying something, if their careers had kicked off immediately the way it did for the older 2. As it stands now, if they had a DP, I'm not sure either would have the cashflow on their own to make Brother 1's situation work for them. So career is the biggest differentiator between those two and Brother 1.