Even if you could find a park for them, after about 20-30 years they can't really be transported because the materials/glue/calk/etc they are manufactured with

Even if you could find a park for them, after about 20-30 years they can't really be transported because the materials/glue/calk/etc they are manufactured with literally cracks, breaks and even disintegrates. AKA, moving one creates a lot of dynamic stress that breaks the roof seals, flooring, plumbing, etc. Leaving them sitting its possible to maintain them such that they remain waterproof, but as soon as you move it, they need a new roof coating at a minimum. Its largely why they lose value too. They need to really be treated as prefab, placed on a foundation and built around. Only one ends up replacing much of the thing over the long run as mobile home parts aren't as generic as normal houses, so one gradually has to replace the lightweight fixtures/windows/etc with normal builder grade hardware which weights significantly more before the mobile home specific parts become unavailable.