The licenses tradesmen carry also tend to be paired with some sort of insurance or bond to back up the fitness of their work. Were it my plumber's license and

The licenses tradesmen carry also tend to be paired with some sort of insurance or bond to back up the fitness of their work. Were it my plumber's license and liability coverage, for example, I'd be hesitate to approve a sweated pipe weld just from video footage. And the market for cheap sonar/magnetic gadgetry or whatever for laypersons to inspect the welds on bathroom plumbing probably just isn't there.