They are just a bookmark, but on Windows, they become a first class citizen on your task bar.

If you are the type to have a ton of tabs open across many windows, this also makes the "app" easier to spot.

You can also pin the app to the taskbar and have it launch with Windows.

Ah I see, thank you!

Continuing on with what the other poster said, when run as an "app" it then also eliminates the regular address bar and other buttons that are common on a full web browser so it "feels" more like a native app. There's also metadata that the app can use to add to the "jump list" feature of the Windows taskbar. You can then also get added as a target to "share" on Windows. There's a number of features that you get access to as an installed PWA at least on Windows compared to just being a webpage in the browser.

Cool! I hadn't considered OS/Windows integration :)

The more minified window sounds useful on my Linux installation, things like Slack randomly fall behind on Electron and stop working