I would be lying if I didn't say that poker makes you lonely. First of all, you always play at times when you should be doing something with other people. Who now claims that you can do both, so I write only from my own experience. A losing online tournament or a very long tournament with no winnings also makes the mood bad and you lose the whole day with it.
On the other hand, poker can connect you with other people if you play in real tournaments more often. It depends on how much you love poker as a hobby or how much you play it just for the money.