Edit: I agree Netflix has good Originals. But most are from the early days when they favored quality over quantity. It is sad to see that they reversed that. They have much funding power and should give it to great art that really sticks, has ambitions and something to tell, and values my time instead of mediocrity.
But TV today is at least 55 inch and in crisp 4k resolution. A modern TV is good enough for most content.
It is not Netflix that killed the movieplex. They were just the first to utilise the new tools. The movie theater became the steam locomotive.
The issue IMO is so few movies are worth any extra effort to see. Steam a new marvel movie and you can pause half way through when you’re a little bored and do something else.
A home theater arguably is as much about the subwoofer and surround speakers as it is about the screen.
Especially the subwoofer has a big impact. When you feel the sound it's literally impactful. At other times, it really helps immerse yourself in the scene, even if it's not a typical bass sound, but like background noise in a busy city street.
The properly configured subwoofer makes you feel like you're there, while it just falls flat on a regular speaker.
That said, the fewest people have a home theater setup, so it's probably irrelevant to why people stopped going to the cinema.