I could say Why Not?
But to answer a question you could possibly answer yourself: -
One is a helmet-mounted camera that I mount on the handlebars.
Another is a dashcam that I can wear on my chest.
Another provides eye protection and was my most-preferred until I got a Robo-Cop visor passed to me (free of charge).
The beauty of dashcams is the way they start recording when the USB power is supplied. They overwrite when the SD card is full. They are portable, so long as the USB power bank is worn on your body, and the cheapest method costs £18.
The attached files are from my video eyeware.
Audi rules apply at roundabouts in UK.