Publishing to the web also avoids the 30% cut that the app stores take, which if you have a popular app is a huge deal. There's also a much lower barrier to entry - visiting a link is a lot easier than searching the app store and installing something. Construct 3 itself is only on the web and not in any app stores, and it's working out great for us.
I think the main reasons developers still make mobile apps is inertia - it's still seen as "the obvious thing to do". It does simplify taking payments too, if your business is small enough that integrating something like Stripe or Paypal is a significant hurdle. And frustratingly there's still a lot of misconceptions out there, as has been mentioned in this thread already - people keep saying "I need a native app for XYZ", all of which can be done on the web too.