The second generation Apple TV is coming up to being 14 years old and the third generation at around 12, which in terms of consumer technology it's a small wonder it's still supported. However, those days are soon up, at least for those using it for Netflix. As of 31st July 2024, Netflix won't be supporting the 2nd and 3rd Generation Apple TV but the company has said, that the Apple TV HD and the more recent Apple TV 4K models are still fully supported.
Apple introduced the Apple TV 2nd gen in 2010 and was sold up until 2012 at which point the Apple TV 3rd gen was introduced. That model was on sale up until the end of 2015 when we saw the larger Apple TV HD, which was originally called the Apple TV 4th generation.
Netflix will work until 31st July, after then Netflix says to buy a new Apple TV or another device which works with Netflix.