While there are a lot of bogus claims of all kinds of miracle insulative coatings and shieldings for audio conductors, in reality, the best material, as an insulator for either data or audio signal conductors, is either PTFE (Teflon) or polyethylene, with as little shielding and protective covers as necessary, for a particular situation."
Oh well at least the expensive HDMI cable scam has been widely exposed.
https://www.google.com/amp/s/www.outofcontrol.online/expensive-hdmi-cables-are-a-scam/
https://www.expertreviews.co.uk/tvs-entertainment/7976/expensive-hdmi-cables-make-no-difference-and-...
https://www.trustedreviews.com/opinion/the-ugly-truth-about-hdmi-cables-2951010
https://www.cnet.com/news/why-all-hdmi-cables-are-the-same/