Pilots already do this. Everything in aviation is "ZULU" time. In computers, we call it UTC or +0000. It actually works really well because we cross time zones so easily.
I would totally be in favor of switching to a universal time zone. But inertia is hard to overcome. Most people don't change time zones very often as they're usually far from population centers and people know that when they take a trip, that's when the time zone will change so for most it's not a daily concern and getting used to a new time zone model would be annoying. When you tell people about the US state of Indiana, they really start to change their minds, that place is fucked up.
Hint: Reykjavik, Iceland is a major city that uses UTC always, no Daylight Savings Time there. I always keep my second time zone on my watch and phone set to that.
I stopped using food delivery apps last year. The prices were just absurd. If I want takeout, I go get it myself. This all started when I tipped a dasher and the service was awful. The guy stopped somewhere with my food for 15 mins and then delivered it cold and was rude when I asked why he stopped at a location for 15 mins. Tips are for good service, not shitty late-delivered, cold, food!
Last night, I looked on Grubhub for a restaurant, figured out what I wanted and the total was $34 (not including tip). I called the restaurant and went and got it myself, $25. That's a 36% upcharge for the app alone! Not including any tip!