In the US, according to HUD and other sources, the existing methods for constructing and installing factory-produced homes or partially prefabricated homes cost 45% to 90% as much as on-site stick-built homes per square foot, depending on the type of construction.
A home that can be moved post-construction can also enable arrangements where the home itself is owned, but the installation site is rented, which can make housing more affordable in places where property area is very expensive.
We also have a problem in the US where all the good quality and low cost lumber has already been harvested. The 2x4 studs typical of stick-built construction are now cut from fast-growing trees of relatively small diameter, such that you can see the curvature in the grain at the end of the stud, the grain is mostly parallel to the longer dimension, it's full of knots, and it changes shape whenever the humidity level changes. You just can't squeeze a good 2x4 out of an 8" diameter log, no matter how you try to cut it.
And yet the overwhelming majority of new single-family homes are still built with wooden 2x4 studs. This is one reason why doors start sticking in their frames after only a few years since a new house was built.
A lot of this is driven by local building codes that will not adapt to newer building methods. There are better, more cost-efficient ways to build houses, and people are literally forbidden from using them. Manufactured homes are instead ruled by the HUD building codes and inspectors, so building something off-site and trucking it in may be the only way to get a home with a particular construction method in a given place.
