https://arstechnica.com/gadgets/2017/12/google-shuts-down-the-apps-section-of-the-chrome-web-store/

More than a year ago, Google announced that Chrome Apps would be removed from Windows, Mac, and Linux versions of Chrome (but not Chrome OS) some time in 2017, and it seems we've come to that point today. Google has shut down the "app" section of the Chrome Web Store for those platforms, meaning you can't install Chrome Apps anymore. Google has started sending out emails to Chrome app developers telling them that Chrome Apps are deprecated, and while previously installed apps still work, the functionality will be stripped out of Chrome in Q1 2018.

As Google explained in its blog post last year, Chrome apps are being killed because no one uses them. In the post, Google said that "approximately 1 percent of users on Windows, Mac and Linux actively use Chrome packaged apps." Chrome Apps came in two varieties: "packaged apps" and "hosted apps." Hosted apps were basically glorified bookmarks, which makes little sense on a real desktop OS but gave Chrome OS users a way to pin important webpages to certain parts of the UI. The more powerful Chrome Apps were "packaged apps," which could run in the background and access hardware like USB ports. Both were desktop-only features, and now both will exist as Chrome OS-only features.