Because more people than you think do not understand this and how delivery platforms work (ie. that restaurants do not control them)

If you're a restaurant and some of your dishes do not handle delivery well then you should not sell them as delivery/takeaway but only on premises. Otherwise you'll have to accept that some customers will be unhappy and leave a bad review.

I think this is a learning curve for many restaurants that are not used to this business model. Certainly in Europe it was not usual for restaurants to offer delivery/takeaway, which was only done by some pizzerias for a long time. Now these platforms are booming and the pandemic has made them critical.