Well, there isn't much benefit to securing DNS or using third-party name servers, unless you also use VPN services and/or Tor to prevent your ISP from seeing what sites you access. However, securing DNS can somewhat interfere with geolocation by websites. Given mechanisms that point to the nearest servers.

But if you are using VPNs and/or Tor, it's crucial to secure DNS. Tor exits do DNS lookups for clients. And properly configured VPN services do as well.