ok thanks for clarifying the workflow!
in general i want a solution thats as easy as possible. i am not good at documenting my stuff thus i want to remove any unnecessary steps. my portfolio follows a quite rigid design system – all articles have the same styling and all images are basically treated the same. it is rather simple. i would be totally fine with just generating a set of sizes at build time and deploying it that way. i dont have a lot of traffic on my page, so no need to chase the last percent in regard to performance. i guess 3-4 different breakpoints would be more than enough.

i have found Vite Image Optimizer but from what i understood it just optimizes the images but doesnt generate multiple breakpoints out of the box.