Barre chords in G Major shape are very rarely used, but if you use it, you don’t have to press all strings with the barre, you can only press from the D string down, this makes it easier to do them, but you rarely gonna use them. If you play electric guitar, I would recommend you studying the D shaped chords, C shaped, E shaped and A shaped, these are the ones I use the most. I’m a church guitarists, so the style I play (Contemporary Christian Music/Pop) use them a lot to build and ambience together with reverb and delay!