responsive embeds (feature request)

using version 2.3.0

I manage a site with lots of embedded content and whenever I browse it on a mobile device, all the embeds get ugly black lines on the top and bottom, which means they are not resized proportionally.

A quick search led me to the option of creating a Child Theme and putting somewhere in it this line:
add_theme_support( 'responsive-embeds' );
but I found creating a child theme too difficult for me (don’t judge!).

source 1: https://thrivewp.com/youtube-embed-wordpress/
source 2: https://developer.ww.wp.xz.cn/block-editor/developers/themes/theme-support/#responsive-embedded-content

Also I found the site https://embedresponsively.com/ which claims to solve responsive embeds one at a time. That doesn’t help me as it won’t scale to the amount of embeds I use and already have in existing posts.

May I request the addition of this tiny line in one of the future releases? Thanks in advance 🙂