Where I live, lane splitting has been legal for over 30 years. So pretty much everyone on the road is used to this and doesn't know anything else.
But indeed, how its done is key. Here its within 10km/h within general traffic speed, with a maximum traffic speed of 40kph.
Pretty much every biker keeps to these rules here.
The idea is that you don't want to be inbetween cars or at the back of a traffic jam when you're on a motorcycle, as you're very vulnerable then.
And of course, traffic jams are shorter when motorbikes split lanes
