What are the privacy implications of using Cloudflare's DoH service, and what data does Cloudflare collect?

Cloudflare states it minimizes data collection with its 1.1.1.1 service. They claim to not log personally identifiable information and only retain minimal data for performance and security purposes. However, as with any service provider, it's important to review their privacy policy to understand exactly what data is collected and how it's used. While DoH encrypts the *content* of your queries, your IP address is still visible to Cloudflare.