Yeah, mine neither, the SNES any my Genesis are pretty tight, both tight enough to lift the console up by the cart, almost enough with the Sega CD attached for the Genesis. (not that anyone should do that) My genesis (pre tmss) also seems to be more resistant to freezing/crashing from bumping the console/cart.
The N64 isn't tight like that though (easily insert/remove carts single handed), but it's always been that way, not a result of wear.

