I had a similar experience trying to find shallow storage chassis that would fit in 2 or 3u. Seems like a no brainer to me to have just a rack mount array of 5.25 bays I can put hot swap cages in but nope.
But it still comes back to the fact i shouldn’t need to make a mini metalworking shop in order to affordably mount hardware horizontally in my rack. Rack mount should be the ultimate in “big computer enclosure” but instead of cool things like having a 2/3/4U massive rack mount water cooling radiator with big quiet fans to silence everything in a computer, it’s getting harder and harder to buy any parts for a non-OEM computer that aren’t festooned in RGB and designed for transparent towers with all the structural issues highlighted in the original article.