Couldn't you say the same about the operating system in general? That is, that apps are limited to the the container provided by the APIs given by the operating system? The browser is only limited by the restrictions given to it by the operating system. There's no reason a browser can't run frame-less graphics-intensive apps with something like WebGL or why it couldn't have access to more of the operating system and hardware or function more like an app.
The main workflow of a web browser (urls and browser history), don't seem any more restricting than having to use an app store to download an app or using the home screen to launch an app. (I would argue that they are, in fact, less restricting). The restrictions are a factor of the operating system, not a inherit restriction of a web-based workflow.
In a way, but there are advantages to running an application in a web-based platform:
- Distribution is easier and doesn't require approval from a third party (such as app stores), providing less of a barrier to entry and more freedom to create what you want to.
- It can be easier to develop and you may not have to provide support for multiple versions of your app (because you can easily ensure that everyone is running the latest codebase).
- Common components/libraries that would be used across different applications can be part of the browser itself or cached for one app and re-used for other applications, instead of having to be packaged into a downloadable runtime application.
- Depending on your application, creating a cross-platform product may be easier and require less development and have built-in functionality like copy-paste and other functionality provided by the browser (history, bookmarking, etc).
- The user and other people have more power to use your application in more flexible ways (due to browser plugins), and the content can be crawled and made searchable/discoverable by a variety of companies.
- The hyper-linking built into the web offers easy, cross-site (and application) integration that may be difficult to accomplish in a native app. In fact, you may be limited to a certain application provided by the operating system (like a particular map provider on mobile)
