You can check out this video from the classic-car insurance company Hagerty to see what goes into rebuilding a carburetor.
Carburetor rebuilds are, of course, easier than engine rebuilds. If you just consider the time involved: three minutes rather than five. You can watch a time-lapse of this Holley Carburetor thanks to Redline Rebuild time lapses. This time, Davin Reckow rebuilds a Holley 4346, which you can find on Camaros, Chevelles, and Novas with a 396-cid V-8 L78. This four-barrel helps the engine produce 375 horsepower and is a 780 cfm dual-vacuum-secondary carb.
Although carburetors are rather complex, they're easily fixable devices that are put on engines with the purpose of blending air with fuel in the correct ratio for combustion to happen in the cylinder(s). Before the days when we had fuel injection, carburetors are what made engines work.
When it comes to the Holley 4346, you're talking about a lot of fuel and oxygen fed into V8s though four-barrels. This high-performance unit originally was put in the '69 Chevrolet Camaro Z/28 and Chevelle, both which had the 396-cubic-inch engine that produced 375 horsepower, partly thanks to this 780 cubic feet per minute dual-vacuum-secondary carb.
But at the end of the day, like all complex parts kept drenched in oil and baked at high temperatures for years, carburetors need some attention as well every once in a while.