“If you encounter a proponent of a an argument contrary to one’s own, surely one should set out a counter argument, not simply dismiss it because you don’t rate them as an individual.”
All easy to say but when you are bombarded with something like what you did, a nearly two hours video to watch in order to see the argument, one has to decide whether to invest the time. Indications as to whether to invest the time or not start by looking at the source and its associations. I have no time and will not discuss with people who are anti-vaxxers, HIV and overt Covid-deniers and naturopaths and homeopaths. Similarly it is futile to discuss on the subject of religion because beliefs cannot be displaced with reason. When the start of a discussion is to discount anything to do with the establishment across the board, and to label mainstream science and medicine as part of a big conspiracy and to ignore public and international bodies, and only believe people who broadcast their ideas and findings on YouTube and personal blogs, and who are not willing to acknowledge the basis of scientific methods and do not acknowledge the peer review process then it really is not worth investing the time.