Well that is certainly true, and in your profession it does seem sensible to clean the cards regularly, maybe even after every use. But cleaning the cards, and thus achieving improved reliability, does not mean that they will last longer, it actually causes extra writing to the card, and since card life is normally limited by number of writes, regular formatting seems likely to reduce card life. If a card was to get fragmented by the dashcam then I can see that regular formatting could significantly increase card life, but as far as I know, dashcams do not fragment memory cards.
Without any proof either way, I don't like to believe any theories! Memory cards are somewhat mysterious, I've yet to see an explanation for how the SD Association, SD card formatter can manage to significantly improve the performance of some memory cards by performing a full format, both when they are new and after some use.