i live in the largest city on the west coast of the USA and the only stores i've found where i can press keyboards is Office Depot and the like, and at least in the stores that i have visited, they have not had mechanicals.
even when Frys was around, i don't remember them having keyboards out and about.
Frys predated the "mainstream" mechanical keyboard boom. If they were still around I'm sure they'd have even more (they were always larger stores).
The Fry’s that shut down was a shell of its former shelf.
If you’re in LA, Microcenter has mechanical keyboards.
They also have a whole rotating robotic wall of 3D filament that works like a physical jukebox.