There is no age attainment required. A person 25 can age in place the same as a person age 65 except for the peculiarities of the dwelling and their own physical capacity.
So often we focus on the people who consciously want to do something about their homes as they age. They want safer entrances, easier to access tubs and showers, safety devices, and electronics installed. This is great, and they should have these items. We enjoy adding them because we know how useful they are.
What about the accidental home - the one that is never consciously declared to be in need of aging-in-place treatments? What can we do? We can note our concern with each other. We can attempt to reach out to the occupants and learn if they are experiencing any challenges of difficulties. They may be surviving just fine - maybe not the way that we would like to do it ourselves, but it is working for them and there are no obvious safety concerns.
Education and communication are large parts of reaching an audience that seems to be hidden from view. Just to identify them and start telling them what they need or what we would recommend they have without learning if there is an immediate need or if there is any interest in having any help would not serve our purposes - or theirs. We can only go where we are appreciated. We might be needed in many more places, but if the welcome mat is not out for us it's much more difficult to create effective solutions.
People are going to age-in-place. It's a fact of life. They will get older in the home or apartment where they are living. The challenge is identifying those individuals who are not experiencing life as well as they might and to offer them help to create a more functional living space for them. For those willing to do this, we are all-in. For those not willing or less willing to have any help, we can only do so much - only offer our support and suggestions, but they have to take the first step.