Restaurants that can absorb the 25-30% hit, for whatever reason, now have an advantage over those that couldn't. The question becomes is this a market failure that needs corrected, or the natural evolution of the food service industry? The case for the former is that you have a vibrant market of pretty high quality restaurants run by their owners as passion projects and have margins that keep the lights on. Squeezing this market because it's now "deliver or die" means that they'll either have to go out of business or reduce their costs which hurts the customer with second order effects -- they will have to reduce their rents by going to a cheaper location that's out of the way, the quality of the food will drop, and/or the staff will be squeezed.
I don't necessarily agree with capping the fee but I don't think supply-chain transparency ever hurt the customer.
If the apps charge too much the restaurants should leave. If that means they end up not delivering what consumers want then they should change their business model or go out of business. If the delivery apps can’t survive under those conditions then they should change their business model, or go out of business.
The hospitality industry has always been ultra-competitive and low margin. Bad restaurants go under all the time. The only thing that is different now is that they have somebody else to point the finger at. The other thing I think they all miss is that without these apps, most of the businesses would have had to immediately go under when Covid hit. Those services were the only thing that gave them a shot of keeping the lights on, and for the ones that can’t find a way to make things work, consumers can do without them.