Thanks to Serkan’s suggestion I was pointed in the right direction to search for editing the wrapper rather than filtering the video itself (even though I would have loved a “filter only” solution.) Nonetheless, I stumbled upon a easy solution here – https://millionclues.com/wordpress-tips/fullwidth-responsive-youtube-embeds/ …
I hope this can assist someone else with the same issue 🙂
Filter:
add_filter( 'embed_oembed_html', 'wrap_embed_with_div', 10, 3 );
function wrap_embed_with_div( $html ) {
return '<div class="hbps-responsive-video">' . $html . '</div>';
}
CSS:
.hbps-responsive-video {
position: relative;
padding-bottom: 56.25%;
height: 0;
overflow: hidden;
max-width: 1200px;
margin: 0 auto;
}
.hbps-responsive-video iframe,
.hbps-responsive-video object,
.hbps-responsive-video embed,
.hbps-responsive-video video {
position: absolute;
top: 0;
left: 0;
right: 0;
width: 100%;
height: 100%;
}