I would argue if there is value in discourse in general, then there is value in playing devil's advocate. ? Devil's advocate is simply a request for discourse, while highlighting the point of it is discourse as such (rather than a stake in the ground / trying to convince people otherwise). IMO, it raises all participants ability to understand both side of arguments, however loathsome either may be.

I think it serves the same value as a falsifiability test. It helps find flaws in otherwise nice sounding or convenient theories.