I would have agreed when I was a kid and a huge TV was a 27" 480i CRT. But now you can get a 85" 4k HDR screen at home, I'd say you can come close. Better than many theaters.
Indeed. It is the same as saying that one should never go out for a walk, because you can easily walk some rounds around the table in the comfort of your own house.
You can still have the "out", like Dinner and coffee at a restaurant. But the specific watching a movie part is "in" whether it is at a theater or your living room.
You committed the fallacy of posting a fallacy without support.
In a theater, you sit in the dark, if you are a good citizen, you don't talk. 90% of any social piece to going to a movies happens at dinner before or after, which you can still do and then go home to watch a movie.