Aside from the abnormally long DST the US had one year during the energy crisis of the early '70s, notice, if you are old enough, that DST gets a few weeks longer every few years. The article states that DST boosts consumer spending. So, I wouldn't be surprised if Congress has been lengthening DST to boost consumer spending.

The article addresses the question of conservation of electricity, but not other forms of energy consumption. From the article, it's not clear whether DST conserves electricity. But I've casually observed it increasing driving/transportation.

If the sun is still up when people finish work, they are more likely to do errands, paint the town, dine out, and so on. If the sun is still up after one errand, another errand is likely. If the sun is still up after a bite of pizza, a trip to the book store is likely. Etc. When you walk out of work or some other establishment in the dark, that's when you're likely to go straight home and stay there.

These away-from-home activities involve not only spending but driving/transportation.

I like DST, but not because it saves energy. It just seems silly to sleep through the best light because the rest of the world is on a late cycle.

Before DST, factories and shops had summer and winter hours. Work might start at 6:30 in the summer and 8:00 in the winter. DST is essentially a standardization of that.