The financial insensitive to ensure only paying users can access the content offsets the cost of the different infrastructure.
YouTube needs to make money as cheaply as possible. They can't afford the processing to guarantee ad delivery and secure content like that.
If the infrastructure/delivery cost of securing content goes up, streaming services can raise their prices.
YT can't really serve more ads. The platform is already pretty packed with ads
This is what "cutting red tape", "smarter regulation" and "taking back control" means.