I commute in NYC, Manhattan, Brooklyn, Queen and Hoboken, NJ area;
I see delivery folks on ebikes or cargo ebikes delivering for restaurants, grocery stores, pharmacies, hardware stores, even Amazon, UPS, FedEx, DHL, etc..
I talk to them when I'm out on my cargo ebike delivering leftover food from schools to homeless shelters in Brooklyn also on my commute in the area;
general consensus is that they can easily make $100 per day just tips alone, the records I've heard is about $300 per day when weather is particularly bad.
Keep in mind that this is a highly concentrated area that have very high demand for these ebike delivery services.
I doubt any of them carry any insurance.
Majority of ebikes I see them riding are Arrow brand:
https://www.roadbikerider.com/nyc-arrow-e-bike-brand/
https://youtu.be/9Rw10qyoWFo
There must be thousands of them in NYC metro alone, if they are not reliable I doubt these delivery folks would use them in such great numbers.
And these guys are out there 24/7, all weather; the foul weather conditions actually bring them more tips and opportunities for work.
More recently I'm beginning to see more 20" fat ebikes, for they are slightly lower to the ground, offer lower seat height, more comfortable ride with fit tires (I suspect)
and less likely for spoke/wheel damage, especially the ebike has cast wheels. The streets of NYC metro can get pretty bad with potholes.
Not sure about Chicago area, but at least that's my understanding from talking to the ebike delivery folks in NYC metro.
Rarely do I see delivery folks riding expensive (above $3k) cargo bikes, with exception of company vehicles or fleet vehicles..
Majority of the delivery folks make their money from being frugal on capital spending, keeping their operational cost down to make more profits.
Which aligns with general principal of using bicycles or ebikes, no vehicle registration, license, insurance or paying for parking or tolls.