I thought the comments on bug 1628024 and the issues described in bug 1628997 begged for a more obvious solution that was being danced around.
Per my comment in bug 1627858:
If we want to retain history (like the old address bar), I think it makes a lot more sense to just bring back the disclosure triangle, like Firefox <75 and current Vivaldi. That way, it retains the same UX it has always had, remains discoverable and can coexist with the new top sites behavior. That requires more thinking though, and is out of scope for what I am suggesting here (File a new bug if you are interested in thinking this through! - I personally never used it.)
I guess I am filing that bug after all!
When I first proposed bug 1558000, I had not imagined that the dropmarker would go away - rather, we'd be adding a new top sites feature. Nor had I expected that enabling top sites would mean that
^ would go away.
Per comment 11 on bug 1628024:
The old list can still be used, if you disable Top Sites in the New Tab Page, or with the ^ workaround.
This is already a supported list in the address bar, showing the dropmarker is very similar to the "Search Tabs" menu item in the tab bar drop marker (which adds
% to the address bar) - why not do the same thing here?
Why should users be forced to choose between top sites and
^? I see use cases for both, and while I basically never used the drop marker, I use
% constantly and appreciate the discoverability added in the menu item.
This would be a simple solution and I think users would appreciate it if it were brought back. It could even be hidden by default, like "Copy Link" (for example) and restored for people who like that list.