I swear people don't use YouTube properly and then complain that YouTube doesn't work. Sure it's shit, but it's your fault for not having subscriptions. If you don't have subscriptions you'll just get served whatever the most popular content is which is usually or just trash.
I'm pretty sure in the subscriptions tab you just get your subscriptions. I think you also get live streams if they're from content creators you've subscribed to but that's okay.
Nah, you get fed mostly similar stuff to what you watched so far.
Watched a bunch of tutorials on how to repair your washing machine? YouTube is going to show you more of that.
Even worse, if you do have some subscriptions but don't watch those videos they will disappear from your feed. Occasionally one might pop back up if it gets really popular. But for the most part they are gone unless you look at your subscriptions.
Even the device you use is taken into consideration. I'm logged into my desktop PC, my laptop and my phone. I mostly watch my stuff on my laptop and phone. My kid watches on my desktop. They get their kids recommendations on the desktop while I get my recommendations on the phone. Sometimes there is a slight overlap. But for the most part it looks like YouTube is treating them like separate accounts.