YoutubeHideShorts.user.js

// ==UserScript==
// @name        Youtube Hide Shorts
// @namespace   http://jdel.us
// @description Hide Youtube Shorts from subscription feed
// @include     http://*.youtube.com*
// @include     https://*.youtube.com*
// @include     http://*.youtu.be*
// @include     https://*.youtu.be*
// @version     0.6.1
// @grant       none
// ==/UserScript==
 
let host = window.location.href;
let url = window.location.pathname;
let ytLinks;
let timer = 0;

console.log ( 'hide shorts start' );
timer = setTimeout(() => {
  hideYTShorts();  
}, 500);

window.addEventListener("scroll", hideYTShorts);

function hideYTShorts(){
  ytLinks = document.getElementsByTagName("ytd-rich-item-renderer");
  for (let i=0; i<ytLinks.length; i++){
    if ( ytLinks[i].innerHTML.search( "href=\"/shorts" ) !== -1 ){
    	  ytLinks[i].style.display = "none";
    }
  }
  
  if (timer) {
    clearTimeout(timer);
    timer = 0;
	}  
  
}

console.log ( 'hidden shorts end' );