quick_unsubscribe_large_yt_channel_per_page.js

// you have large amount of youtube subscription channel (100+), the this code work well at page https://www.youtube.com/feed/channels
// if the number of subscription is smaller, please change  querySelectorAlltarget
var ele = document.querySelectorAll(".yt-uix-button-subscribed-branded");
for(var i=0; i<ele.length; i++){ 
	ele[i].click(); 
	var unsus = document.querySelectorAll(".overlay-confirmation-unsubscribe-button");
	console.log(unsus[unsus.length-1].click())
}