If you want to open Edge without actually wanting to open it, just accidentally click on one of the advertisements in the main menu or any info area widget. Those ignore the default browser and always open Edge.

Heavy tweaking of Firefox UI (fortunately userChrome.css and user.js are still available, even if hidden in undocumented about:config options), heavy tweaking of labwc, using a custom labwc theme, tweaked GTK theme.

Window resized to get it all in one readable screenshot.

Damn, that looks absurdly ugly and even more like a foreign object on the desktop.

I hope this usability nightmare can be completely disabled or toned down so the browser looks like a native program compared to the rest of my programs.

The browsers sooner or later will always respond “18+” and do not ask the OS.