delivery charge is because you're taking labor out of the store, where that person could be doing things like cooking, serving customers at the counter, answering calls, cleaning, or doing management duties.
that money goes straight into the owner's pocket. not the driver's.
that being said, i don't understand the point of tipping a delivery anyway. probably feels nice to be out of the workplace for a bit. some probably even stop to grab a bite to eat or play on their phone in a parking lot. i would in the same position.
however, when it comes to restaurants. tipping is a thing because people didn't want to wait around for their change and debit machines weren't always a thing. then bosses started paying servers less because 'they get tips so thats part of their pay'. so then it became a regular thing to tip, because if you didn't, the next time you come around, the server would probably give you just the service they only 'have to', maybe less even.
though some places just give everyone a fair wage and split the tip between all the staff.
speaking of tips when I was younger I tipped the pizza dude $40
when i was younger, my bro and friends would always make me get up and go answer the door when they got here. every single time.
one day i was not giving a stuff about anything, pizza came to like... $22 or so, handed the guy two $20 bills and just said keep it. wasn't even my money.
they never made me go and get it again. and any time i get asked, i remind them of it.