I get out and gig, between 2 and 6 times a month. I couldn't live without them.
There is so much you learn playing in a band in front of a live audience that you cannot possibly get from playing alone at home, with friends or in a recording studio. It not a case of whether you are a better or worse musician, it's just a broadening of the experience. Timing, anticipation, you have to watch, listen, be prepared for the unexpected and then work out how to deal with it.
I for one hate the pressures of a recording studio, give me a live gig any day.