From the The Coming of the Post-Industrial Society:
When productivity is low, time is relatively cheap. When productivity is high, time becomes relatively expensive. In short, economic growth entails a general increase in the scarcity of time.
This is from a later section in Bell’s great book, in a section called “The New Scarcities.” Before the abundance of mass production, it was material goods that were scarce. Now that most people have what they need (and more) materially, it is abstract things that become scarce, specifically for Bell information, coordination, and time.
While experiences to be had and objects to be enjoyed multiply, time remains finite. While we now have hundreds of restaurants where we can eat dinner, we will only have enough time and appetite for one dinner per day. And furthermore the cost of choosing where to have it and the anxiety that we might be having it somewhere better or with someone better are additional costs which were not felt as acutely as before.
We are time poor because we are rich in so much else.