Building a polished, stable, feature-complete mobile app for the two major platforms generally costs about a million dollars if you want it to be world class. Of course you can reduce scope or polish or pick only one platform, but that's roughly what it takes.
Who's going to pay to develop the apps that these local businesses use to do online ordering, to sway customers away from Uber Eats et al? The reason these organizations are achieving market penetration is because their UX is polished. Yelp made a whole (predatory) business off of small business owners being bad at websites.
I'd love to see it become more decentralized via private arrangements, but there are real costs to entering the market due to software developers not being cheap. I'd also love to see a resurgence in use of the web for such things, but despite being able to bookmark websites to one's homescreen, it's still not quite at the point where using a website feels like an app, and users care a lot about that stuff.