I struggle to understand the use-case. What does this actually offer me over just using a normal web browser with maybe a customised new tab page? I made an account with a throwaway email to play around with it, and I honestly didn't understand why I'd want to use this over whatever workflow I have now.
In the abstract, I can feel out there being some kind of use case I'm not thinking of. Maybe something along the lines of having a familiar mental model for organizing the data in the browser, (not the data in the web apps running in the browser). Things like bookmarks, tab groups maybe, browsing history.
But what is shown is more of an honest attempt to create a full OS in the browser which will always be inherently inferior to the operating system the browser is running in, even with advances to browser engines.