GrubHub tends to lean more on merchant costs (like commission) than consumer fees. This is why lately you may have seen (a) scary looking news articles about GrubHub taking half of a restaurants income, and (b) cities talking about emergency orders to limit commissions.
But either way, the economics are roughly the same: getting food made and delivered to your door is really really expensive. It just comes down to how that gets sliced between restaurant, consumer, and driver.
I'm in a suburban/semi-rural setting and have found Uber Eats to be more reliable than Grubhub in most cases. It seems like UE might open up GH to more of these markets where restaurants have been slower to warm up to working with a service like GH than restaurants in an urban center.
But either way, the economics are roughly the same: getting food made and delivered to your door is really really expensive. It just comes down to how that gets sliced between restaurant, consumer, and driver.