Time well spent
Have you wondered why Youtube videos automatically start playing a new one, once the one you have been watching ends?
It is because many online services compete for our attention. For example, they are interested in which news timeline would grab your attention the most. If you ask yourself, in the end of the day, what sort of news timeline you would consider time well spent, it will probably be a very different timeline than the one served to you.
Here Tristan Harris argues that what teenagers do on social media is different than what they did on the phone in the 70s. The reason is that in the 70s there was no arms race for using the phone more, even though there was still an economic incentive to use the phone.