Its actually much more beneficial to use a local DNS server even for a single user. A single user will keep querying for DNS requests since OS/apps cache DNS only for a minute or so. Local DNS will keep cache for the full TTL of the record and thus reduce the number of DNS requests that go out of your network. Plus there is Serve Stale feature which improves resiliency. For privacy, depending on your scenario, you can either run recursive resolver or use encrypted DNS protocols to hide DNS from your ISP. There is also support for configuring SOCKS5 or HTTP proxy to route requests via another server or via Tor network.