> but I'm sure there are concerns that people here would know something about. Please educate me!
Even though DoH encrypts the DNS metadata, it is still visible to the provider so you have to trust the provider not to expose your DNS requests to third parties. Since Cloudflare is currently used as the default, they act as a huge choke-point for users who have opted into DoH and there's no real way of knowing if such a provider is not sharing this data with unscrupulous third parties.