Not sure how all the services work, but I believe the drivers are given delivery job offers where they see information about the delivery location and payout estimate, and they're able to accept / reject jobs based on this info. Therefore it's not necessarily that there weren't drivers available just that the drivers chose different jobs. It might be that you're in an area that isn't particularly profitable for deliveries (homes or restaurants too spread out). I believe you can also tip more / tip upfront to make it more likely that drivers accept the job. Although these services present tipping as an optional gratuity, if you don't tip up front it could lead to your job sitting in the queue forever since it's not as appealing to drivers as other available delivery jobs with included tips.
