This is true, but a lot of newer homes have a cooktop and separate oven, rather than a drop-in or slide-in range as used to be popular. This is nice because th

This is true, but a lot of newer homes have a cooktop and separate oven, rather than a drop-in or slide-in range as used to be popular. This is nice because the oven is at a better height (and it's pretty convenient to have a double oven), but the consequence is that gas cooktops are almost never wired for 240V. If the cooktop is on it's own circuit then the upgrade can be done without rewiring, but I don't imagine that's a very common arrangement, it's probably shared with a few outlets, or microwave, etc.