If you want a fast site, fix your images. Rename files to be descriptive...

https://list-wiki.win/index.php/Should_I_Include_Colors_Like_Red_Apples_in_Filenames%3F_The_Truth_About_Image_SEO

If you want a fast site, fix your images. Rename files to be descriptive instead of using generic tags like "IMG_001." Write alt text that actually helps users and search engines understand the context