A use case could be to build a recipe to encrypt a message with your public key. Post the link on your website, now anyone can click the link and encrypt a message to you.
Becareful with that approach. I saw a company that used the QR generator function to setup MFA/TOTP codes on phones. I filed a bug since they were sending the TOTP seeds to a third party. It's a little silly in this case, since cyberchef is open source and the seed shouldn't leave the browser, but it's still a third party and it's easy to generate the codes in your own page.
https://gchq.github.io/CyberChef/#recipe=To_Base64('A-Za-z0-...
A use case could be to build a recipe to encrypt a message with your public key. Post the link on your website, now anyone can click the link and encrypt a message to you.