The expression “hustle culture” refers to workplace environments that place an intense focus on productivity, ambition, and success, with little regard for rest, self care, or any sense of work-life balance. (www.talkspace.com)
As a trend it dates back a few decades ago:
In fact, this culture has existed since the 1970s, at which time the development of the industry was accelerating and employees were required to work at a fast pace without any time limits. In 1990, technology companies also began to dominate the world so that a new standard emerged for young people to overwork. (www.bfi.co)
Curiously Google Ngram has no reference about this expression so, apparently, it is a quite recent coinage.
I can guess it is an American expression, but when and possibly by whom was “hustle culture” coined?