I think the VCS looks just fine on a 13" CRT, especially if it has a composite video upgrade. Anything larger or newer is a mismatch for the hardware; a 4K HDTV isn't the way the VCS was designed to be viewed.
frankly I think the 16 bit era consoles are hit harder than the 2600, at least the 2600 doesn't use the crt blurring on checkerboards or vertical stripes to make additional colors which look aweful on modern screens