Depending on how far you are away from uni, living in halls can actually be cheaper than / similar price to commuting.
I always find that I work better at uni - working at home is nigh on impossible because my family don't understand that I can't always be there to look after the elderly relatives / go to the supermarket / do x / y / z, because I need to do work, and that involves long periods of interrupted time. My flatmates don't interrupt like that.
Being involved in societies (which can, in itself, be beneficial to your career, and is always beneficial to your enjoyment) will be much easier / not impossible if you live in halls. Often the activities put on (not just socials!) will require transport outside the times that public transport operates; some sports societies start their day at 6.15am; others won't finish until 10/11pm at night.
And it will make you more independent, and make you learn how to cook etc. etc., within a fairly safe environment - halls have both security and pastoral support, which cannot be said for the private housing that people live in for subsequent years, so it's best to be broken in easily in halls.