The latest Edge Canary version started disabling Manifest V2-based extensions with the following message: “This extension is no longer supported. Microsoft Edge recommends that you remove it.” Although the browser turns off old extensions without asking, you can still make them work by clicking “Manage extension” and toggling it back (you will have to acknowledge another prompt).
At this point, it is not entirely clear what is going on. Google started phasing out Manifest V2 extensions in June 2024, and it has a clear roadmap for the process. Microsoft’s documentation, however, still says “TBD,” so the exact dates are not known yet. This leads to some speculating about the situation being one of “unexpected changes” coming from Chromium. Either way, sooner or later, Microsoft will ditch MV2-based extensions, so get ready as we wait for Microsoft to shine some light on its plans.
Another thing worth noting is that the change does not appear to be affecting Edge’s stable release or Beta/Dev Channels. For now, only Canary versions disable uBlock Origin and other MV2 extensions, leaving users a way to toggle them back on. Also, the uBlock Origin is still available in the Edge Add-ons store
Why is there a sidebar for tabs? That seems wasteful for all the screen space it takes.
Edit: From what I see it tries to do everything that is a job of a window manager/desktop environment. There are various solutions to have workspaces, etc. that you can use globally, so I don’t understand why would anyone use this, unless you are on locked system like Windows or Mac.