"Set tabs aside" in the previous Edge browser was a nice feature but it can be better.
Tab grouping can be seen as method of session management.
Vertical tabs: What's coming in the next version looks good but it's basic.
All Chromium browsers have a tab grouping functionality (must be enabled in about://flags) but it's not very helpful.
The attached video shows Firefox browser with the 'Simple tab groups' extension button moved to the top left corner of the browser. It works but it's slow and its interface is inconsistent with the look of the browser. I think the Edge team can do better.
With the proposed feature, users would not have to open multiple browser windows when there are too many opened tabs as well as having the ability to manage their browsing sessions.
We haven't seen much about vertical tabs feature to call it "basic". at least let the feature come, evolve, improve and then we can judge it. that short video Microsoft released was a simple demo, didn't reveal much info.