Occupy Wall Street was the birth of the left in the US. The US hasn't really had a leftwing since the 1920s. It created a whole class of activists that went around couch-surfing and protesting at major events. A few years later #NoDAPL happened and a huge chunk of the people involved in that were also involved in Occupy. As someone who was really involved in union organizing all the way on the opposite side of the country, I can tell you how much these organizers had an influence. We saw a huge shift in attitudes towards labor organizing after that and a huge influx of energy from people who first got into organizing through Occupy. Occupy also gave us Graeber and so many strains of leftist theory related to eco-socialism, communalism, and many other "hot" leftist theories today.
I'm sorry but I feel like this author is really out of touch here. Perhaps to someone who only interacted with it through the news, it seemed like they didn't get anything done. But that energy didn't just dissipate. It spread to almost every facet of American leftist organizing