Cloudflare should offer disposable addresses on your own domain. One click enablement. Why not.
https://blog.cloudflare.com/introducing-email-routing/
However, disposable email addresses on a domain that you personally own can still be profiled by the domain name. Services like Firefox Relay try to preserve anonymity by sharing the domain name(s) among all users, the same way VPNs share IP addresses among their users.
Jokes aside, they're awful to Tor users (Infinite captchas), and break sites on anything not running JS.