The extension button is there and it wasn’t there before.
It serves no purpose for me (I do not have that many extensions).
Devs went to an extra length to disable any customisation on this button.
It is on a position where I previously had a different button and thanks to my muscle memory I click on it when I want to do something else.
So naturally, I want to get rid of it. I know it’s petty but it is my computer so I want it to behave that way.
Yeah, I would not mention Gnome as some kind of standard worth aspiration.
If you really have to remove that icon because it bug you that much in Firefox and you really need to reclaim all that space. Then type in about:configin the menu bar in Firefox. Click on Accept the Risk warning message and continue. Then in the search preference name type in the flag extensions.unifiedExtensions.enabled. Then just click on the toggle button on the top right bar to change it from true to false. Close the browser and relaunch.