There is also a difference between continuing to participate, and shutting the door behind you so no-one else can participate. That's what we are getting in property markets in various places right now and it's not necessarily malicious. Young people can't afford homes even with well paying jobs, because the property game was rigged to build wealth for those who got in early and now the bar of entry is too high.
I think sport is a good example, a natural ageing out process means there's constantly room for up and coming talents, and importantly people can see that there is room and so they know they can invest the effort to aim to take that spot.
In various ways right now, it feels like there's no room, and there may never be room. Why invest the effort? Why save money for a house if prices are always just continuing to climb? Why work hard when the wages are too low to progress because the c-suite hoovered up all the cash?
Old people want to be engaged and do something meaningful and influential as long as they can. I imagine the majority of them would agree in principle that younger people should have more of a role. Just that someone other than them should be the person to step aside and make way.
Do you honestly think that when you are the same age, you will be willing to end your role as a productive member of society for the sake of the "younger generation"? Even if you don't have enough to retire and maintain your current lifestyle? What will you do with your remaining time after that?