Yes, unfortunately the design of the public DNS system is highly centralized, there are no alternatives.

"Quad9 advertises itself as a global public name server that aims to protect users against malware and phishing. Quad9 is operated by the Quad9 Foundation, a Swiss non-profit, public benefit foundation whose goal is to improve the privacy and cybersecurity of Internet users, based in Zurich.

Quad9 is not an open source project, but uses open source software as the basis for its service. For example, Quad9 uses Unbound as a recursive DNS server, Knot Resolver as an authoritative DNS server and PowerDNS as a management DNS server2. Quad9 also collaborates with other open source organizations such as NLnet Labs, ISC and CZ.NIC3."