It is the most powerful until you specifically want to buy led torch light then they put the cheapest possible light in it.

That could be legit. Windows runs things when idle like indexing, scanning for malware, updating etc. As soon as you move your mouse it reduces cpu usage. Which technically looks like a malware trying to run in background without user knowing it.

Finally linux is getting popular enough to make viruses. Yay?. Insert gru meme here

IMO “default” has to be simple and user friendly. I’m not saying kde is not user friendly but it has overwhelming amount of options which I personally think is too much. of course there are people that use these but i think something like gnome is very simple and more approachable. I think this is why many distros use gnome as default. I would consider myself to be a mid level user i started with mint linux -> ubuntu -> debian -> manjaro -> garuda -> arch -> fedora -> and finally settled on nixos. I have tried lot of desktop environments and i liked kde very much but the amount of customisation made it a chore after a while. i can use the defaults perfectly fine but if something has a toggle to choose different options i try all of them. Which i agree is a not applicable for everyone. But i think sometimes taking option away from user works example ios and macos. So, i settled on gnome. I understand it is a personal choice. I’m just trying to explain why it might not be a good default from my perspective.