A channel where a dude works full time and YouTube is a side gig wouldn't buy a $250k sound chamber to measure how loud the fans are on a crappy prebuilt (GN - the people who made the initial video about LTT). There are significant benefits to being full time dedicated to creating this content, and being paid well in response. Something like this would only be possible following your model if they already made tons of money outside of YT, in which case, they're already rich so what's stopping them from going full time doing what they want anyway and uploading those videos?