But nothing about how to actually achieve one, or, "what makes people feel upbeat at work".
Reading an article that would go into that topic would have been more interesting.
What's nice is that various people have already figured out formulas to motivate workers. It goes by different names depending on who you talk to, but some examples are Deming's 14 points for management, lean, Toyota production system, continuous integration/delivery, DevOps culture. (With some overlap, of course.)
These things create an environment where workers are allowed to be motivated and essentially everything desirable for a company comes out of that state.
The person's paycheque is how you satisfy those basic needs. Yet a workplace doesn't necessary become positive.
The next rung up, intimate relationships(well fraternization is generally bad for the workplace) but friends is a big deal. Some businesses have realized this. They hire based on personality similarity. If everyone are friends, you can only grow so large until personality will collide and it becomes a problem. If everyone are friends, it can lead into positivity but it can be tricky.
The answer is the next step up. Feeling of accomplishment.
“The deepest urge in human nature is the desire to be important.”
― John Dewey https://en.wikipedia.org/wiki/John_Dewey
Everybody likes a compliment.
A workplace that has compliments will rapidly become a workplace that is positive.