So far, YouTube TV has been available in most major platforms. However, it wasn’t available on the PlayStation 4 as Sony essentially prevented third-party live TV subscription services from being available on the PlayStation 4. The reason being, of course, PlayStation Vue — Sony’s own live TV subscription service.
As you may know, Sony is shutting down PlayStation Vue due to the expensive cost of network and content deals. And so, it makes perfect sense for other alternatives to be available on the platform.
So far, YouTube TV is the only third-party live TV subscription service available on the PlayStation 4, and I assume other services like Hulu and Sling TV will also make their way to the PlayStation 4 soon.