Provider vs. InheritedWidget

Provider is not a must, but should.

First of all, it's promoted by Flutter Team and flexible enough to handle almost any state-management solution.

It might not be fair to say that InheritedWidget with dispose because Provider has too many different use cases and inherits some optimizations probably you won't find anywhere else.

If you use InheritedWidget in large application, build methods always rebuilds whole build method. But with Provider you have Consumer widget which is can be very specific to control specific blocks of build method, so you have more efficiency. Also listeners have less complexity than InheritedWidgets'(O(N) vs O(N²)).

The problem is since Flutter was intended to be a UI framework at first, the default state management solutions are also UI oriented.

Lastly, since you'll need different state-management patterns for different projects, one package-for-all scenario is invaluable imo.

Yes. Provider is indeed mostly features based on Inheritedwidgets.

If you want to make your own, then that's fine. But you'll quickly realize that, without provider, you'll have hundreds of useless repetitive lines.

Provider basically takes the logic of InheritedWidgets, but reduce the boilerplate to the strict minimum.

The Flutter docs have a good section about this where they're talking about state management in your app (a big part of which is passing values down the tree).

Flutter has mechanisms for widgets to provide data and services to their descendants (in other words, not just their children, but any widgets below them). As you would expect from Flutter, where Everything is a Widget™, these mechanisms are just special kinds of widgets—InheritedWidget, InheritedNotifier, InheritedModel, and more. We won’t be covering those here, because they are a bit low-level for what we’re trying to do.

Instead, we are going to use a package that works with the low-level widgets but is simple to use. It’s called provider.

So as of late 2021, it seems the recommendation is to use the provider package unless you need lower level access- in which case you could use the Inherited* widgets. For example, if you wrote your own version of provider then you'd need that lower level access.

The doc I quoted above is at https://docs.flutter.dev/development/data-and-backend/state-mgmt/simple#accessing-the-state