KDE is more similar to windows, Gnome is maybe closer to MacOS.
But generally, KDE felt always a bit “super user” to me, and I found the amount of customizability and features more overwhelming than useful. Gnome is simple, clean, and I prefer it for that reason.
They place ads in the search results.
If you disable your ad blocker, the first search result will almost always an Amazon ad. I test searched for “Headphones” and it also shows a row of JBL headphones at the top ala google shopping, which is an ad as well.
Really, they make their money the same way as google, they just don’t track your searches and site visits.
Then why not use 1? It’s closer to pi than 10 and even easier to calculate with.