One of the benefits of Chrome in general is that it is available on a wide selection of platforms including Android, Windows, Mac, Linux and of course, Chrome OS. Which does mean that many apps have also now made their way to the various platforms. While Android is an entity onto itself, the rest of the platforms make use of Chrome apps, ones which are web-based in principle, but offer extended functionality through the Chrome browser on those platforms. However, that is going to change soon as Google has now confirmed that they are completely dropping support for Chrome apps (not themes or extensions) on Windows, Mac and Linux.
For those who do use Chrome apps, there is not going to be any good news here really, as the apps are going with no real replacement or alternative being offered. However, one silver lining for those users, is that the ending of support is going to occur slowly, with the eventual full closure of Chrome apps expected to take place in early 2018. Until then, there will be a systematic dismantling of the support for Chrome Apps, which will begin later on this year when newly-published or released Chrome apps will not be accessible by any of the mentioned platforms. This will however, not affect already-existing Chrome apps, which will remain accessible by users and able to be updated by developers. Following which, in the later part of 2017, the Chrome Web Store will stop displaying Chrome apps on the various platforms. This will be in preparation for the eventual ending of support via Windows, Mac, and Linux, which Google states will occur "in early 2018". At which points Google notes "users on these platforms will no longer be able to load Chrome apps."
In terms of why Google is doing this, it seems there are a few reasons, although they do somewhat overlap. Firstly, Google notes that "approximately 1% of users on Windows, Mac and Linux actively use Chrome packaged apps". For those wondering what a 'Chrome packaged app' is, this is a type of Chrome app that many will be more-familiar with as they are apps which emulate a normal desktop app. In contrast to 'hosted apps' which are entirely web-based. So actual user numbers seems to be playing a major role in this decision. However, Google does also go on to explain that "there were certain experiences the web couldn't provide, such as working offline, sending notifications, and connecting to hardware". An issue that Google points out is not so problematic anymore with the evolution of web apps. While the last reason is a very simple one with Google explaining that as they continue to try to "simply Chrome", they feel it is time to "begin the evolution away from the Chrome apps platform".
It is of course, worth pointing out that none of this will affect the actual Chrome OS platform in any way, shape or form, as this seems to be the one platform which will retail full access to both new and existing Chrome apps "for the foreseeable future". Which makes sense as Chrome OS does primarily make use of these apps as their main routes to functionality, in spite of some Chromebooks recently gaining access to Android Apps. To some, this news won't come as a total surprise as it has seemed as though Google was winding down non-Chrome OS support for Chrome apps, with various changes including the removal of the Chrome app launcher earlier this year. That all said, if Google's numbers are correct, then this won't actually be a change which affects that many users on the various soon-to-be not-supported platforms.