Well, not to defend the method, but they are required to use an appropriate mesh size that targets the specific open fishery. In theory this lets smaller fish pass through and larger fish can’t get far enough into the opening to catch their gills. Fishermen are to change their web to suit the target, by law. Of course it’s not perfect, there will be by-catch, and I can’t say how often their nets are inspected. As I recall though the penalty was significant, along with scorn among peers.Gillnets are selective relative to fish like windshields are selective relative to bugs . . .
One thing I believe is true, and lost on some, is that commercial fishing is a livelihood. These guys don’t want extinction either. Generally at least, they want responsible management as well.
That was my experience anyway.