How long can we expect a used, acceptable condition Atari 2600 cartridge to last if played less than ten times yearly?
To be fair this really depends cart to cart. Speaking as a vintage collector and having a large 2600 cart collection it really depends on how it was originally used. It also depends on things like solder joints on the connectors. More importantly the semiconductors can fail -- remember that these cartridges are approaching 50 years old. Most of my cart failures come from issues like these but there are others to take into consideration. Most of the Activision carts were cheaply made in Taiwan and have had higher than normal failure rates in my experience.