You seem to have misunderstood this post from a team member:
90eed6f9-1257-4917-8357-f7ff5981cf52-image.png
I translate it for you:
There will be no such whitelist in the medium term, .i.e. years.
Said;
I don't want to install an extension if the browser has a way to toggle "dark theme"
In this sentence lies the whole problem.
1.- The ‘if’ does not exist.
2.- Extensions are not evil, in fact the Vivaldi UI is indeed an extension.
Said:
especially also for other devices.
Android, Windows, Linux etc. are different OS and therefore with different approaches to the solution.