Yes, taking the lane is an option. And I sometimes take it. Most often when I don't do so is if there are curves in the road where someone can come in fast from behind the corner and hit me. I mean, I'm allowed to not be a mere few centimetres/inches from the side of the road, but I try to weigh things against each other. Sometimes it is prudent to be a third or more out from the side, sometimes it's better to hug the kerb.