I don't see the value in using an extension just to automatically watch YouTube in HD. Maybe 10 years ago, but now we got Newpipe.
Also Google Search has gone downhill for quite some time now. Why should I install an extension that reverts the enshittification Google has deliberately created?
DDG, Qwant, searXNG maybe even Brave or Kagi are better options. If you like Google Search so much, at least use Startpage.
It is a metasearch engine, so you can tweak the sources of the results, default language, etc. I personally use all the default plus some more engines and all languages, then reduce results if I can't find useful information. It has made searches easier for me, since you can find all types of information with just one click (Search | Images | Files | Academic | etc.) and multiple languages, but it can be not so welcoming to people that want simple searches.