Check out truck stops. Plenty of supersized folks lumbering around among the bottles of Diesel Treat, logbooks, CB radio displays, and chrome reclining titty lady silhouettes, and plenty of XXL, XXXL, and XXXXL t-shirts depicting howling wolves, motorcycles, Indians, Dale Earnhardt (Senior, of course), Confederate flags, and “Lord’s Gym” on the shelves.
Some stats from one mfg (demographic is older and well off, not young) from a large number of units shipped
XXS 2.7519% XS 11.5124% S 23.8672% M 29.6669% L 20.7260% XL 11.4747% XXL 0.0010%
XS 0.0147% S 5.1304% M 17.8179% L 33.3477% XL 30.3354% XXL 13.3522% XXXL 0.0015%
Walmart sell $5 fruit of the loom shirts at the 2x-4x level that fit like a 3x-5x (pocketless fits better, idk why) shirt in those paper bins that are on the shelves in the men’s department.