Never had any sensor failures related to ethanol. I think O2 sensors are just made in bad and good runs. I owned one Chrysler, built in 1984, that went through a O2 sensor, every 40K. The car was programmed to run rich, it was a 2.2L Turbo Series I. 97 and onward none of my new cars have suffered failures in the O2 sensor dept. (knock on wood).
I concur though on the carb rebuild issue. In some cases, I have torn the carbs down and cleaned them, to find aluminum parts slowly being corroded by the alcohol/fuel combo. Jets clog, floats stick, and I have even seen fuel lines dissolved to the point that you touch them, and they disintegrate.
Cleaning a carb once in a while is not so bad... but it gets old once you have to do it 2 times a season.
Another poster said that some fuels may have ethanol, which are “ethanol free”. This is possible, I guess, I don’t know the industry, but I can tell you a gallon of that stuff with no stabilizer, sitting in a 1 gallon can, outdoors for a year, will crank a engine. E10 will not. Once the alcohol evaps, what is left will not burn... not sure if it is because of all the water left behind, or damage to the gasoline itself.
Clarification: “what is left will not burn”
what is left will not burn in a gasoline internal combustion engine.