Someone nailed it in the thread above related to the -time/+money, but after a couple of years working on it, I realized that the people that use those services are not the public that would go to a restaurant for a gastronomic experience, and that's ok.
At least for me, the biggest 3rd or maybe 4th order effect of the food delivery industry and their dark/gray kitchens is that the concept of having a nice cooked meal locally is almost over, with some exceptions.
Due to the over-optimization of the kitchens and the offset in terms of revenue that restaurants can have (i.e., orders without increasing the real estate), we have a bunch of pre-set mounted meals in almost all restaurants, and the probability of eating something tasty and unique is very low due to that.
The irony is that, at least in my experience, the best non-chain and/or fine restaurants that I found were the ones in some shopping centers in the Nordics for a simple accidental association: none of those has any possibility to have food delivery due to hard physical constraints, and my assumption is that, since they do not have this possibility, they have to deliver the best meal possible to have people return and build a positive reputation.