A service people want to use is typically one with redundancy and high availability. Your laptop could overheat, have a drive failure, spontaneously lose its wifi connection, or a million other things. It's fundamentally unreliable.
only reason we need a scalable system, is to handle high demand
Scalability isn't just about distribution. It's about reliability and convenience - two things your system as described lacks by design. A video file that no one but you has ever seen has the same exact degree of accessibility as one served to millions.
We could EASILY EASILY EASILY done it ourselves.
This is the copium talking. If it had been easy to do and monetizable, it would have already been done. That's the other part of the problem here. There is no incentive for anyone to use this system to consume or distribute content other than to decouple from Google. Opposition to an existing service is not enough of a motivator for people to use a system. It has to provide some comparative benefit that outweighs the cost incurred by continuing to use the other service. The big thing that Youtube has is, obviously, content. Exabytes of it. Your new service would have...nothing. We have left the age of services starting up and gaining massive movements of people behind them. We are now in an age of the internet in which the inertia of existing services will carry them decades into the future. Youtube is now too big to fail, and too big to be replaced.