It is as simple as providing a service that has all content I want to watch. Look at things like Spotify or Apple Music. They don't have everything, but it's enough and has effectively stopped my pirating music.
Same with Netflix. It stopped me pirating because of the convenience, but since everything got separated in its own service again, I started up my own plex server. I'm not jumping through a million hoops to watch a stupid show or film...
Not to mention keeping game saves in sync. I’m experimenting with syncthing for my pirated games, but I have to admit that just getting the Steam version sounds much more sensible now that I’ve my Steam deck.
I'm not sure. I remember I was waiting for it to go on sale when I needed it, and it happened pretty quickly. But I don't know if it happens at any set intervals.
That's not an entirely valid comparison in that the other platforms that got redesigned don't give the end-user the option to still use the old design. Chances are that if they did, a lot of people would stick to the old design there as well.
Same goes for the Reddit redesign. People have been up in arms about new Reddit ever since it's been introduced.
I'm pretty sure they'd be much less up in arms if the new version didn't suck as much as it does, though. Same probably holds true for the redesigns that were introduced for Youtube and Facebook.
Cheers!