Yes, I had a gas tankless. It still needed electricity to heat water. If your electricity goes out you instantly have zero hot water, unlike a tank you can usually have warm water 2–3 days if you conserve. Maybe less in a very cold climate. The hot water never runs out. You can fill your bathtub and then take a long hot shower, and then all your grandkids take a shower, you have constant hot water. Although, if you have multiple faucets open at once you can have a situation where there is not enough hot water to go around, but if you get the right size that shouldn’t be the case. That’s similar to a tank anyway. It does not mean instant hot water at the tap. The water still needs to travel through the pipes the same as a tank water heater. There are appliances you can buy that you install right at the kitchen sink or bathtub That basically give you instant hot at the location. Takes up less space than a tank.