I'm not a Kagi user and don't have any hard info. But I find DDG frustrating with searches. It tends to do fine enough with technical searches, like software/programming searches that I make. It's other random searches that it often fails with. DDG will fail to find the nuance in my search query, the results will flat out not be what I'm looking for, so as a sibling comment mentioned I'll fall back to using !G with some regularity.
I've stopped using Google due to their captcha being so frequent and frustrating. I don't want to spend 60+ seconds answering 6 captchas purely because I use Firefox with privacy settings/extensions.
No Tor, no VPN. Nothing too far out of the ordinary.
I usually search in a private tab, enhanced tracking protection set to strict, uBlock with most default filters enabled.
Oh and a "Google Search Fixer" extension because the make the UI much worse for Firefox. Maybe it's one of my extensions, but DDG never traps me in captcha hell.
I've stopped using Google due to their captcha being so frequent and frustrating. I don't want to spend 60+ seconds answering 6 captchas purely because I use Firefox with privacy settings/extensions.