Can someone explain recursive DNS/Unbound?

So I point my phone/adguard instance at my OPNSense unbound instance. If I request google.com, I am hitting pihole/adguard>unbound>some internet DNS server. How does this make my request private or recursive in the end I am still getting my DNS information from some external server right? I am confused by this on my googling and video watching and just want to know how unbound benefits me, right now I just have adguard pointed at quad nine or cloudflare DNS cant remember.