remove-yt-thumbnails-on-mobile.js

// ==UserScript==
// @name         Remove YouTube Thumbnails on Mobile.
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://m.youtube.com/feed/subscriptions
// @icon         https://www.google.com/s2/favicons?sz=64&domain=youtube.com
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    const style = `
      <style>
        .cover {
          display: none !important;
        }

        .media-item-thumbnail-container {
          display: none !important;
        }
      </style>
    `
    document.head.insertAdjacentHTML('beforeend', style)
})();