Microsoft introduced Sidebar search functionality in Edge over a year ago, and it evolved over time to become something where you can launch services like Microsoft Outlook. It is getting even better with Microsoft adding the ability to resize the Sidebar in Edge Canary.
Reddit user Leopeva64-2 claimed that the new resizeable Sidebar is available in the latest Edge Canary update, but we have not been able to reproduce the change in Edge Canary Version 107.0.1417.0. Hence, it could be a controlled rollout. Thankfully, the Reddit user has posted some images explaining how it works.
First off, you do not need to enable a flag to be able to resize the Sidebar. It is available by default if Microsoft has rolled it out for you. If you are one of the lucky ones, you need to hover your mouse pointer over the space that separates page content from the sidebar pane. Upon doing so, you will see a double arrow that allows you to resize the pane.
As pointed out by the user, there are some limitations to it. For example, you can not resize Favorites, History, Downloads and Collections, and Outlook panes. But this is something that can change in the future, and we hope it does. Luckily, all other sites and apps you add are resizable.
Recently, Google has started working on a similar Sidebar functionality for Chrome. But all it does at the moment is display the search results. Of course, Google would like its Sidebar to be much more than that in the future.