Until you want to watch that one kinda obscure thing that isn't adequately seeded... then your out of luck. (I'm aware of server "pre-seed"/enhancement options this just assumes you want to watch something that isn't seeded or pre-seeded)

That's because it isn't done legally, and therefore augmenting the network with a few "supernodes" (I believe that's what napster called them) is a big no-no. You could say the same about Netflix/HBO/..., by the way. Watching obscure things (that aren't worth Netflix or the copyright owner's time to negotiate rights for ... good luck). And if the present trend continues, and Disney, and Paramount, and ... start their own streaming platforms with exclusivity, well, popcorntime is going to be the vastly superior option in a year or two at most.

In the other case for a distributed example, you have the Steam platform. Obscure things download quickly and without much delay. And steam avoids the "rights negotiating" problem by being a marketplace.

That doesn't make p2p video streaming useless though. Or even inferior.

There are solutions to this problem. It just starts costing a lot more money when you need to guarantee content.

As if Netflix and HBO have everything you would ever want to watch?