If he could get a truly “Free market” to De-develop I say
go for it.
All he would need to do is have a large majority of the population agree with him. It also cause a need to put a stop to all immigration. Only a developed country can take in large amounts of unskilled people. Most government social programs would need to stop. The less development you have the less income you have above what you need to live on. We could all live in fly over country. Work in the fields in the hot sun all day.
Maybe he hasn’t thought this though thoroughly. I though think many liberal would like it in flyover country.
If you de-develop you will have less machinery and fertilizer, so you will need many more acres of land to produce the same amount of food. A lot of the less productive former farmland which has been allowed to return to the wild will have to be cleared and plowed (horse or oxen only) again.