It definitely looks like Youtube Vanced is using a lot of battery. On my personal Note 10+ I don't have any crazy battery drainage with normal Youtube.
Update : My battery life was pretty much the same with normal youtube but I switched my phone to 1080p and the battery life is extremely good now. Still disappointing I can't get normal battery life on 1440p like on my s10+
Strange you should go to a Samsung store and get that check out and maybe get a replacement because I use 1080p on daily basis but if you still cant get advantage of the big battery, I would go to your local samsung store.
Got it I mean you might as well talk to an operator from the samsung members app- live chat and ask for an estimate if you need to pay or is it going to be a free replacement