I think you misunderstand the point. Of course we need more technical capabilities in Europe. But we don't need the companies providing said capabilities to have the influence of Meta, Alphabet and co. And influence comes with size. Replacing a US based monopolist with one headquartered in the EU doesn't get rid of the monopoly.
So no, we don't need an European tech-giant. What we need is more in-house know-how and more medium sized companies.
GNOME has too. There it's called nightlight
Budgie might ship with an applet, that enables the functionality as well (not sure, it's been a while, since I last used this DE)