It’s as easy to find live games on YouTube as it is to find videos on Twitch. You type the game name and at the top click the “live” tab. If you subscribe to a user who goes live and you’ve enabled notifications (the bell) it alerts you when they go live. It’s really simple.
I’m subscribed to quite a few channels. The problem with the notifications is that I can’t distinguish between notifications for live streams or those for videos or Community posts. The only notifications I would care about are for live streams, as hose happen “now”, I can watch videos why time. I don’t wanna be spammed with all the notifications for normal videos, while I still want them in my notification bell menu on the site (so notifications need to be on for the channels).
YouTube can do videos and live streams, but it doesn’t let me distinguish between these fundamentally different things in a meaningful way.