Wikipedia suggests about 1 micromort per 10 miles on a bike [https://en.wikipedia.org/wiki/Micromort] so maybe it's 1/2 micromort in an urban area and 1 in the suburbs.
It's quite gamified due to the per drop pricing and tips etc. I found it hard to not ride like a maniac.
And I didn't even need the money, I did it because it seemed funny to basically get paid to exercise.
I'd also suspect that someone who rides a bike for their job is likely likely than the average person to die in a crash. People that die in bike accidents are disproportionately not doing two things:
1. Wearing helmets
2. Being sober (20+% of adult cyclists that get killed are too drunk to legally drive a car [1], and "drunk cyclist sober/car driver" is actually a lot more common in fatal crashes than "drunk driver/sober cyclist" [2])
I don't want to victim blame, but there's relatively easy things you can do that drastically reduce your risk of dying on a bike.
There's also some intangibles, like someone who rides all the time is going to be more familiar with safer routes (OTOH they may be encouraged to ride more recklessly to maximize profits?). Even with a pedal assist bike, I'd also imagine that the health benefits would partially offset that micromort.
[1]: https://www.iihs.org/topics/fatality-statistics/detail/bicyc...
[2]: https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/...
Having been a delivery driver, and well, just casually observing others - this is likely to be an enormous factor.
Motorized scooters in particular seem to behave in frankly absurd ways, mounting the pavement at 15mph etc.
Because otherwise you'd have truckers banging it around at 130kmh for 10 hours at a time.