Yes, I do record for evidence in case of a crash, crime, traffic violation, etc.

In 2014 I was the victim of a hit-and-run, and my action cam recorded the crash. I was struck from behind by a pickup truck driver, but the camera was mounted under my handlebar, so the suspect was never identified nor apprehended.

The video is still on YouTube, and a local news agency shared some of it in their news report. The video was immediately useful for the police officer at the crash scene/crime scene and for his police report. The video evidence immensely aided my insurance claims, and all 3 claims adjusters made a point to praise the video. They all appreciated how clearly it demonstrated fault, supported my version of events, and exonerated me.

Another benefit to having that video record was that I was able to see what had happened to me, because my memory was blanked and fragmented for 20 minutes or so.

I now have a Sony HDR-AS100 helmet camera and a Xiaomi Yi Lite tail camera. I have used the Sony to record a traffic violation and license plate (at night with streetlights and my headlights for illumination) for a traffic complaint I filed with the local PD. I carry multiple spare batteries, and it is indeed time consuming to remove, recharge, and replace batteries, attach & remove all of the electronics, and transfer, store, and edit the video files, so I can understand the reluctance of others to deal with the added hassle and inconvenience.

The camera is attached to an adhesive clip secured with cable ties.