Disabling unnecessary or unneeded functionality: https://design2seo.com/blog/web-development/wordpress/disabling-unused-wordpress-features/
Change the allowable image size put in an HTML SRCSET Attribute size (of course 16384 is a fairly large screen) setting into a Child Theme's functions.php file;
function new_srcset_max($max_width) {
return 16384;
}
add_filter('max_srcset_image_width', 'new_srcset_max');
When WordPress creates "Thumbnails" (AKA Alternative Image Sizes (AIS(s)), the default quality compression is set to 85% (supposedly). The below setting in a Child Theme's functions.php file preserves 100% quality;
add_filter( 'jpeg_quality', create_function( '', 'return 100;' ) );