They pivoted from having a bunch of people managing mailing DVD's to people to having a bunch of people managing computer servers. It is really different and there is no reason to assume they would succeed at that, if they built a subpar service they would have lost.

Someone will reinvent cable by bundling services together and charging people for content in which they aren't interested.

It'll happen as soon as the fragmentation is worse enough for people to loose interest and willingness to pay for them separately.

Netflix still runs a dvd rental business, with a much higher offering of titles (less content restriction than with streaming)