> what appears to have happened is that the local housing market now values those condos higher than it does their detached home.

I think it is even more benign: they are trying to stay in the same area and in their area (likely sparsely populated, given their 2-acre lot) the available condos are giant 4-level new developments that cost a lot.

They can still downsize, just need to move further away from where they live today. My 2c.

I think this is basically the heart of the matter. Given the large-lot neighborhood they're used to, finding a condo that's going to feel "comfortable" to them is hard enough to begin with. Then, factor in the accessibility issues like finding a one-level, 2-bedroom condo with no steps, no multi-step front stoop, and preferably with a no-step shower and a garage: you've narrowed the market dramatically. You're basically in "retirement community" territory, which is significantly more expensive per square foot than SFH, not less. Having just been through this, it means locating somewhere you swore you'd never live and sticking out like a sore thumb as a senior in a "starter" community.