1, will lead to cowardice and weak will.
If you live in your own world all day, even if you communicate, it is through the internet, which is a limiting factor. So when I am away from home, I don't know how to solve all kinds of things in my life. Because you haven't faced them, you will choose to escape, live a life divorced from reality and become weak.
2, autistic, isolated from the world
But let's put it this way, if you often stay at home, you can't see the wonderful world outside, and you can't understand the information outside, so you will have a strong sense of despair. When interacting with people, you will be at a loss, autistic, and will refuse all the news from the outside world, thus parting ways with reality.
It is very serious to lose your family.
Maybe you think it's good for otaku, so don't worry about saving money. Yes, such people are unambiguous even if they eat instant noodles at home for a month, but in other ways? They also shop online at home, which is not a phenomenon of saving money. In fact, people who stay at home like this are the most unsuccessful.