Aging in place applies to literally everyone, whether they have any physical limitations that impact their mobility or not. It doesn't matter if they have sensory or cognitive impairments - as long as it is safe for them to live on their own, with a spouse or family member, or under the supervision of a caregiver.
Some people like to extend the idea of aging in place to a move that places the individual into another dwelling - an assisted living facility, group quarters, cluster housing, high density apartments, or some other type of congregate living. There may be good reason that someone would want to choose a move like this, but this bypasses the original intent of aging in place. After the move, people may then age in place in their new housing, but the idea of needing to move to find acceptable housing in which to age is not what the term suggests or implies.
Aging in place is not - and was never intended by definition - to be a two-step or two-stage process where people move from where they are now into a new dwelling and then age in place from that point. The whole idea is that people do not need to move, They can continue living in their current home as it is with no modifications of any kind - even though some are indicated and would make life more enjoyable and easier for them, or they can choose to make improvements to their present home to assist with access, comfort, convenience, and general safety.
While it's true that people can find a new dwelling and then begin aging in place in that new abode, and likely never move from there. This is counterproductive for the most part. Unless the current home is unsafe, in a neighborhood that is not conducive to aging in place there, or for various other reasons does not present a good lifestyle scenario for the occupant, they should remain where they are and age in place there.
Aging in place does not suggest that anyone needs to or they they must move-and-age-from-there but that they age in place - place being the operative word. It means wherever they are right now is where they continue to be, and they either make the most of it as it is, or they enlist the services of aging in place professionals like us (including contractors, designers, DME providers, and health care professionals), well-meaning family, friends or neighbors, or community-based or social service agencies to help them adapt their living quarters for their current and projected needs.
Aging in place is a strategy that takes people where they currently are living and determines what needs , if any, they have personally, or that their home presents to them, and then sets out to accommodate those needs, based on budget, medical necessity, and other priorities. It is based on meeting people where they are, where they are living. It does not mean that they should find another, possibly more suitable home, move into it, and then begin aging in place from that point forward. While technically they would be aging in place, they would be defeating the main premise which is to allow them to stay where they are and not need to move.
While moving into another home may have an attraction for some people, the whole idea of aging in place is make this unnecessary and allow people to remain where they are - in a home they are familiar with, in a neighborhood they know, with all of their "stuff" in tact, and all of their recent (or long-term, depending on the length of time living there) memories present.