I'm pretty sure it's a reference to https://www.youtube.com/watch?v=Qc7HmhrgTuQ

My answer is zero, but most people's answer is much larger. Having said that, how many Google services and systems are there for us?

None. And I would not trust a service today that depends on any Google service either.

I'll visit YouTube for free entertainment sometimes, but I hardly depend on it for anything, and I really wish more creators posted their content elsewhere, even at a price.

Nothing that they actually made themselves after I (I'm not OP) have stopped using Google search, it's just YouTube now.

What has Google actually created that's successful, in house, other than search & gmail?