Around here (DC suburbs out to Appalachia), it’s a mix of both. The closer to the city, the more likely the mobile home is in a trailer park. Though there aren’t many left - most that I’m aware of have been bought/closed/redeveloped.

In terms of increasing the supple of affordable homes for people who are in suburban or semi-rural areas, mobile homes really are a mixed bag, for the reasons listed (which is then exacerbated by PE firms buying up parks and milking the residents dry).