Some features from Edge that I think are easy wins and well worth copying:
1. Ctrl + K to clone/duplicate a tab - Seems other browsers don’t tend to have a keyboard shortcut for this, and I can’t be the only one who regularly clones a tab to branch my browsing without getting confused.
2. Tab stretch on close - A feature recently removed from Edge for reasons that escape me: when closing tabs using the cross button on the tab itself, the tab in question used to disappear, and then the remaining tabs would widen to take up the vacated space such that the cross for the next tab would align with the mouse pointer automatically. The tabs would retract back to their natural width upon moving the pointed away from the tab bar. This makes it much easier to close many tabs in quick succession, although I can imagine it might also increase the change of an unintentional double click, which is easily undone and less likely to be a problem than the feature to be useful.