8 hours at work, 8 sleeping, that's still 8 more left. I would be surprised if you took all of them to cook and clean.

Even with 4 hours of chores a day, that's still 4 hours to do whatever you want. Doesn't mean you spend them all that day, or all of them socializing. Maybe you use mondays to study, tuesdays you spend more time cleaning so wednesdays you can go out do something.

Also consider that if you strictly socialise in a work context, most of those relationships will grow distant relatively quickly when you or they leave for another company, which means it's harder to build long lasting friendships. Those can be really handy at times of transition in your life, which is where work friends usually fail first.