It kinda depends what you’re looking for. For technical stuff DDG is much better than Google (I don’t know about kagi) but for local information Google still gives better results. Google seems to return what it thinks you want to search for and not what you actually tell it to so for exact searches it’s always worse. If you’re not sure what you’re looking for Google can be better sometimes.
I’ve gotten pretty used to DDG’s interface. I’ll try kagi at some point but I don’t know if I’d use it full time.