People don't worry about it because it just isn't a concern. The duty cycle of any particular lidar in any particular direction is very low and so for any two

People don't worry about it because it just isn't a concern. The duty cycle of any particular lidar in any particular direction is very low and so for any two lidars they will have their beams pointed at the same place very infrequently. It happens but in order to, say, drive in the rain self driving cars need to be able to reject a certain amount of sensor noise. I've had a gagggle of robots using planar lidar, where the risk of interference is much higher, all work together in the same room together and not noticed any degradation in performance. The reasons lidars are so useful it that they're very directional in a way that radar isn't. That means that an effective lidar jammer can't just emit enough to interfere when the lidar is pointed at it, it needs to cause every other object present to also emit that strongly. This is possible but will cause nearby people to catch fire, at which point it probably doesn't make sense to call the object a "lidar jammer".