I think you are just trying to be that guy. I go to this website, pick what I want, pay and some time later what I ordered gets delivered to my door. What's there to get?
Food temperature is a personal preference, some people are really picky about food being hot/fresh, some aren't. I prefer the taste of room temperature food over hot food so "sitting around for 20 minutes" would be a feature for me.
... and then jumping into his new C300 to deliver it.
I'm not sure I can process that. New Mercedes, let's put miles on it delivering fast food...
And some people like really like McDonalds and don't care for the fancy stuff.
It's not for me, but it basically it boils down to "people like different things than me."
I know someone else who can't understand why anyone would ever play video games "its time and effort for zero reward."
Some people enjoy doing work on their car, while others would rather pay someone to do the work for them.
Humans aren't the same.
Justeat delivers from fast food.
Deliveroo costs more because it's providing a delivery service for restaurants that don't normally deliver.
So I'm getting good food. When in a restaurant, things sit in a kitchen for 10 minutes waiting for the rest of your order anyway. 10 minutes in a thermal bag is the same.
"To me this ruins the meal"
shrug, I'm not sure what you're expecting anybody to say. I can't really change your mind on what is hypothetical situation for you. I've ordered plenty, it's generally no worse than the quality I would get in the restaurant (other than the presentation in a bespoke takeaway box not a plate).
Also, what kind of presentation are you expecting for a burger anyway? It's a burger, with some artfully surrounding chips? Ordered to go, it's a burger, with the chips in smaller box instead of surrounding the burger.
But at that point you're basically just objecting to all delivery food ever. Which is fine but, like, you are aware that it is a huge industry and has been for decades and people do like it? Convenience trumps artistry (and optimum temperature) for many people a lot of the time.