"Unsafe" is an emotionally laden term that's hard to discuss, because emotions are subject neither to measurement nor discussion. If you change that to "risk" you can have a rational discussion.

Most calculations of relative risk indicate the risks of not exercising (as in bicycling) are about six times higher than the risk of death while cycling. I think it was the British Medical Journal (but I could be mistaken) than came out with a factor of 20:1. That is, the benefits of bicycling are 20 times higher than the risks.

Emotionally, that's more than safe enough. Cycling is also fun!