I think the bike delivery labor market is super different from the delivery driver market. You are much more likely to find people "gamifying" it as bikers than as drivers.
If one does plan to deliver (bulky) non time-critical items, payment drops significantly (almost no tips, fixed fee for each parcel).
As I wrote earlier, payment is not linear. It depends on the region, day and time. One can make a lot of money in 1-2 hours on some evening, but also sit idle for another 8 hrs in a parked car waiting for another order. (to my knowledge, one has to be booked into the uber eats app all the time and broadcasting the current location. So one is encouraged to still hunt/stay next to interesting restaurants, usually big chain stores like Mc Donalds, Starbucks. IMHO it's not a plausible add-on business for regular Uber/taxi drivers or other gig economy jobs like harvesting electric scooters)
Let's say one can make 40$ in 1 hour but 50$ in 9 hours.
The one profitable hour is probably within the evening rush hour, lot of traffic, down-town, short distances. 0 parking lots.
The other 8 hours are past midnight, in the morning or between noon and evening. Longer distances (=>less drivers, less orders => bigger coverage => no surge pricing).
Overhead costs stay the same.