Says who? I can easily find 16” tires in plenty of widths/ratios. Also, the wheels on the Summit site are mostly 15’s and don’t come with center caps or trim rings, meaning each wheel will cost 250-300 complete.
I’ve got 16/8 torque thrusts and finding a good set of 200 tread wear, A temp proformace summer tires is limited. Sure you could find some all seasons, but you’d be better off with 15’s or 17’s as more tire options are available as most modern cars are running 17’s or bigger, and that what the market is demanding. Truck tires are a different story...