The problem here isn't so much the age of the people; it's the whole structure of our society. In almost all indigenous cultures, age confers respect and honour because it signifies experience and that those people have both their past and their vision of the future to guide their ideas and suggestions of best paths to go forward for EVERYONE.
In our society, the only vision is about acquiring and maintaining power, territory and wealth. Who gets to be the next King or Queen. And that means war or constant political trade-offs to maintain those 3. Obviously, the older you get, the less able you are to fight and so you're delegated to the sidelines. So that's what we do with elders in our society; delegate them to the sidelines. Especially the ones without wealth, territory or power.
Essentially, we've created a system that's upside down. Youth rules and elders are discarded into homes where nobody really cares about them.
Ideally, we would create "ruling" councils with all genders, colours, ethnicities and ages of maturity (18 and above). But that only happens a few centuries into the future as you see on Star Trek's Federation. And even there, it's still mostly white humanoid men and women ruling and "captaining" starships. But at least there is a high level of respect for ALL cultures.
Enough for now. I mostly love what you write but this paragraph seemed just a bit off kilter.