Coming from a country where media consumption used the be expensive, the reason people pirated entertainment was mainly due to cost. Not because it was inconvenient to see an ad.
Streaming will still be miles more convenient than piracy. All I have to do is turn on my apple tv, grab the remote and watch whatever I want, whenever I want. I don’t have to dig through some torrent sites, download it, then stream it to the tv.
You don't have to do that these days, either. There's software out there that will happily keep tabs on your favorite shows and films and download them as soon as they're available via torrent/newsgroup/etc., and then drop it directly into Plex, Kodi, or wherever, automagically.
Just like streaming, but without the cost.