yes-i-am-sure-i-want-to-leave-youtube.user.js

// ==UserScript==
// @name         Yes I Am Sure I Want To Leave YouTube
// @namespace    https://github.com/lionel-rowe/
// @version      0.1
// @description  Disable "Are you sure that you want to leave YouTube?" redirect page
// @author       https://github.com/lionel-rowe/
// @match        https://www.youtube.com/*
// @icon         https://www.youtube.com/favicon.ico
// @updateURL    https://gist.github.com/lionel-rowe/130b59a8cd06bdf359f9d4888baefb94/raw/yes-i-am-sure-i-want-to-leave-youtube.user.js
// @downloadURL  https://gist.github.com/lionel-rowe/130b59a8cd06bdf359f9d4888baefb94/raw/yes-i-am-sure-i-want-to-leave-youtube.user.js
// @grant        none
// ==/UserScript==

const eventNames = [
    'mouseover', // before clicks
    'focusin', // before keyboard navigation (Tab + Enter)
]

for (const eventName of eventNames) {
    document.body.addEventListener(eventName, (e) => {
        if (e.target.matches('a[href]')) {
            const url = new URL(e.target.href, document.baseURI)

            if (url.href.startsWith('https://www.youtube.com/redirect?')) {
                e.target.href = url.searchParams.get('q')

                // remove all existing event listeners by overwriting innerHTML
                e.target.parentElement.innerHTML = e.target.parentElement.innerHTML
            }
        }
    })
}