I trust the app to be a more reliable intermediary between me and the restaurant rather than ordering directly. I trust that the app is more technically sound (I've had problems ordering from 'bespoke' apps and websites) and won't forget my order or route it to different city/country or something (things that have happened). Some apps offer tracking of the courier (can be nice to have) and give features that 'bespoke' options don't have.

Also, you get reviews and discoverability of options. I can go to a different city and see all the delivery options immediately.

Unlike a lot of people here, I've had great experiences with food delivery apps. Not doordash (not a thing where I live), but others. I knew people working as delivery bikers and they said it can be a decent way to earn a living while you're studying. The flexible nature of the work lends itself well to that.