To do the same thing with ACF that WP does with images in the content area is possible, but will be some work. Basically you need to build an srcset for the image. It was done in WP by incorporating this plugin into core https://wordpress.org/plugins/ricg-responsive-images/. You should probably start there and look at the code. You may even be able to use the same filter and get WP to build the srcset for you. I haven’t done this. While I know it’s possible it will take some work to get it done.
