I don't really get worked up by "testing" that norcal does. He doesnt make scientific claims and seems to just be making videos about the testing that he does to try and decide what equipment he is going to run. He even says stuff like "i think i get better traction over crappy roads on wider tires and therefore for my riding ____ is the best for me." Is that theoretically valid argument? No. Grip on an ideal surface is only a function of normal force and CRR, contact patch has nothing to do with it. In the real world is he right? Maybe?
Reality is that this stuff is really complicated and trying to create repeatable results that are distinct enough to make an unqualified claim is hard even with better experimental design and better instrumentation. You hear that from Peak Torque now too in the way he discusses results. Its a change from a few years ago despite his experimental design and instrumentation being among the best of the popular you tubers.
This is a very long winded way of saying that I think experiences are still worth sharing and discussing even if they aren't "scientific" as long as you acknowledge the limitations of your insights.