As per comment https://bugzilla.mozilla.org/show_bug.cgi?id=1706232#c3 and https://bugzilla.mozilla.org/show_bug.cgi?id=1706232#c4 I suggest to add "Send tab to device" to the File menu, e.g. after "Email Link ...".

Feel free to change this task to be cross-platform if it makes sense to be.

Totally agree, the current way where the different sharing functionality is spread all over the browser, for no apparent reason, is horrible UX. The File menu has been the customary place to place sharing functionality for more than a decade on macOS, so this enhancement is a no-brainer.

Also relevant is bug 1512851 ("Add Share Menu to File Menu on macOS"). When both of these are implemented, the sharing UX would make a lot more sense.