You don't need an internet connection or the app, but that's the most convenient way - you can enter a PIN on the bike itself to unlock it.

I think the appeal (at least for me, I considered one but never got one) is that it makes the bike harder to steal. Someone can't just ride off on it after they cut your lock. I worry about leaving my $600 bike out in public, so I'd be super paranoid about a $2000+ bike.