Paying an extra $10-12 in tips and fees to have some courier a meal directly to your door is ridiculously cheap, a courier service would charge 4x as much for a similar courier trip.
I completely understand the grocery deliveries, it's a trade off, time vs. money. Personally I think the delivery costs are to high, but I also live four minutes away from the supermarket on foot. For others it's one less thing to deal with and they can do the shopping in the evening when the kids are put to bed or have the groceries ready when they come home after a long day. For them the delivery fee is well worth the value the service provides.
It's the $10+ for getting McDonalds multiple times a week I struggle with. People are free to make that choice obviously, but I feel like the delivery services are praying on people who are already struggling, especially when they team up the Buy Now Pay Later companies.
The rest of the delivery charge is ‘baked’ into the price of the food.