I use Cloudflare Workers for:

* Serving a standard security.txt file for all websites within my account

* Automatically rewriting the case of URLs for a CMS that doesn't support case-insensitivity

* Adding security headers to sites that don't support adding them locally (e.g. third-party hosting)

* Proxying requests elsewhere directly from the 'edge', rather than having to run my own proxy

* Serving static config files, e.g. mta-sts.txt, proxy.pac