I guess the idea behind the request is about creating webp / avif version of image ( and/or breakpoints! ) during uoload itself. This way convertion is conducted only once ( server performance ) and it shoult be possible to integrate with upload providers like AWS S3.

strapi-plugin-local-image-sharp mentioned by others does not provide those features.

The problem with is that let's say there is a malicious attacker, they can use unlimited combinations of format/resolution to generate huge amout of image files, it can quickly fill up the server's disk and probably even cause a DoS

The mentioned plugin converts it on the request, and not on upload. If you are looking for a conversion at upload you should look at this feature request: https://feedback.strapi.io/customization/p/add-webp-and-avif-conversion-to-strapi-plugin-upload

This can be done with https://github.com/strapi-community/strapi-plugin-local-image-sharp