I'm making two points here, and it's worth separating out.
First is pure utilization. App drivers get paid while on the road and while idle, store drivers get paid hourly while on the clock and usually have some useful work to do. The average pay of road & idle time has to be worth the driver's while, and the store driver has more valuable work they can do, so the economics make more sense.
Second is the largely tip-driven pay differential while on the road vs in the store. 3 deliveries an hour at my store, more at places that trade off service times for throughput. Average of $3-4 per run, with a tendency for higher tips for customers further from the store. (Funny example: there was this one house at the exact furthest corner of the store's delivery area. They were extremely nice and tipped like $7. These facts are not coincidental.) But this basically becomes a cross subsidy of in-store work by tips, and there was a decent chunk of tension between drivers and management over this. Usually it took the form of "do your assigned side work and then you can go home", and since doing dishes was the "bad" pay of the shift, this disincentivized malingering too.
As far as I can tell for non-tipping countries, drivers tend to use employer-provided vehicles and fuel, so it turns into a more straightforward hourly job and loses a good chunk of the piece-work and quality incentives.
First is pure utilization. App drivers get paid while on the road and while idle, store drivers get paid hourly while on the clock and usually have some useful work to do. The average pay of road & idle time has to be worth the driver's while, and the store driver has more valuable work they can do, so the economics make more sense.
Second is the largely tip-driven pay differential while on the road vs in the store. 3 deliveries an hour at my store, more at places that trade off service times for throughput. Average of $3-4 per run, with a tendency for higher tips for customers further from the store. (Funny example: there was this one house at the exact furthest corner of the store's delivery area. They were extremely nice and tipped like $7. These facts are not coincidental.) But this basically becomes a cross subsidy of in-store work by tips, and there was a decent chunk of tension between drivers and management over this. Usually it took the form of "do your assigned side work and then you can go home", and since doing dishes was the "bad" pay of the shift, this disincentivized malingering too.
As far as I can tell for non-tipping countries, drivers tend to use employer-provided vehicles and fuel, so it turns into a more straightforward hourly job and loses a good chunk of the piece-work and quality incentives.