One of the most important features of the current Edge is the "Set Tabs Aside" feature. But the new Edge Insider doesn't reflect this, and is only following Google Chrome. I'd like to see more of the Edge's features come back.
@HiSky It looks like Set Aside tabs is being replaced with Collections. I've been experimenting with Collections -- which allows users to collect, organize, share and export content -- and I'm coming to believe that Collections works more efficiently than Set Aside tabs does.
I particularly like the fact that Collections captures sources and creates citations automatically, which saves a lot of time for certain kinds of work.
A few things are still missing (I'm on Dev Version 78.0.268.3), such as the ability to re-open all tabs in a collection, but my understanding is that the missing features are under development and will be rolled out eventually.
In any event, take a look at Collections and see if it alleviates some of your concerns.