Why are framed closed panels seldom used?

Framed Closed panels are used because of the following reasons:

• They are very good in insulation.
• The closed panels include wiring, plumbing and a good interior finishing.
• Installation of plumbing and wiring is very quick in closed panel system.
• These types of framed panels are good in erection.
• The walls and sub-floors are having a good bondage with joist in between.