In many of the fancier suburban neighborhoods around here, gaslights can be found lighting up the outsides or either posts, or mounted on the walls of homes. Most of the ones I have seen have been mantle type, but I have seen a few flame type in the newer neighborhoods that are trying to look fancier and more "upscale"....never figured out why wastefulness is considered upscale, but I guess I don't understand, because I'm not there.
Mantle type gas lights use very little fuel, and produce a good amount of light. I have a portable Coleman backpacker's lantern that will run over 24 hours straight off of a single 16 pound propane cylinder. It is BRIGHT, and gives off about as much light as a 100 watt bulb. Using Thorium or other radioactive materials in mantle wicks nowadays is outlawed, but there has been a host of other interesting technologies that allow less gas to make more light.
Still, despite the fact that flame-type gas lights are wasteful, they do look nice, and I sort of imagine the days when streets were lit using these lanterns versus the ugly sodium-vapour lamps that are commonplace these days. One of my annoyances too is the fact that we over light the outdoors at night anyways. The dimmer street lighting during the gaslight era was probably plenty to get the job done without being overkill, like much of our outdoor lighting is these days. Yes, outdoor lighting deters crime, but you pass a point of diminshing returns.
Sodium vapour electric lamps are primarily used today because of the high light output per watt used, but the light has a terrible color. Even mantel style gas lights would give off a more pleasing color than those ugly things, and they are not that bad. Still too, they wouldn't be subject to the unreliability of electricity which is a common issue around these parts. Those neighborhoods I was mentioning with the exterior gas lights on their homes? Well, they stay nice and lit up when there's an outage. In fact, I cannot ever remember a gas outage in my city the entire time I've been alive, but power outages are very common!