I find it great as it groups your thought processes. You Google something and it opens a group for that, then you read something in one of the search result tabs and need to go to some links there/Google more stuff - that's now grouped under it so you can easily find things for that thought track. Once you are done, you can close all the tabs in one go.

As far as I'm aware you can't nest groups in edge? I'm trying now and can't even reliably create a group and it scrolls randomly when trying to move tabs around.

That final part is my point - as far as I'm aware the other browsers have nothing as powerful as this. May need to check if there is anything new though.