This will explain a lot of why some freehubs are loud and some are not. It is really about design.
https://cyclingtips.com/2018/12/hub-...of-engagement/
I have experienced more loud freehubs mountain trails than on road bikes. The major advantage of DT, Chris King, etc is the ease to service the hubs which is desireable when riding in adverse conditions. They also tend to have sealed bearings as opposed to cup-cone that is another benefit riding in dirt, mud and the like.
John