I saw a joke post a few years ago
that went something like this:
Legal DVD->Insert, watch unskippable copyright warning, watch unskippable advert for a film you will never watch, watch another advert for a film you will not watch, watch series of logos for companies you don't care about, get to menu animation forcing you to watch another 20 seconds of stuff from the film you are just about to watch, navigate menu, press play, watch film
Illegal DVD-> Insert disc, press play, watch film
I knew someone who would buy a DVD then download a pirate copy of the same film just so he could watch it without going through all that nonsense
Regarding adverts, some streaming channels continue to play adverts until you click to stop them. If you don't press the button then you get constant adverts.