In a vacuum, sure.

In practice, the government has moved from speed cameras (benign monitoring) to ALPRs (pervasive surveillance) without the public blinking. In practice, many auto manufacturers (Telsa, Hyundai, GM brands) have made it a matter of regular policy to ship home audio and video data from drivers’ cars to use for marketing and surveillance.

Backup cameras are a small drop in the bucket compared to other transportation design choices if you’re serious about a Vision* Zero endgame, and in my book, the potential for abuse makes them a liability rather than an asset towards that end.