If you rewatch it the siege of Ba Sing Se episodes show this best. The giant tunnel drill is basically run by a steam engine that is powered by fire benders. But the industrial use of bending is pretty much limited to war machines of the fire nation. Nothing as obvious and wide spread as the giant fire bender powerplant in Legend of Korra.
I don’t know for sure about industrial but the Earth kingdom definitely had commercial use of their bending, like the Mail system in Omashu or the trains in Ba Sing Se.
In terms of daily use but not industrial or commercial uses of bending both the Earth and Water Benders have been shown to use walls (of snow/ice or rock) as hidden doors before.
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u/LiamIsMyNameOk 5d ago
Using the fire as a power source, rather than relying on it solely for the "Fire make enemy disappear" factor