Not true.. you get stuck it's too late. If you THINK you need more tracrion put it into 4 low OR push the mud/snow button.. once you are stuck or in a ditch meither will help you.
I drive until I get stuck in 2 wheel drive, engage the 4 wheel drive and pull on out ....
it all depends on how badly one is stuck ... a slick road and need some more traction or 40 ft off the shoulder in the middle of a farmers field in 3 feet of snow
I went plenty of places in the 1990's in a VW Beetle - Open diff and No front drive axle