There are employers out there that notice hard work and dedication to do more than the average employee that just shows up and does the bare minimum. Sometimes it can take time for this to come to fruition when those small efforts add up over time.
You are right in that some workplaces are just toxic and the boss can be psychopathic lol. Working hard has to be combined with also working smartly which can be assessing the nature of the place you are working in and deciding if your hard work will be rewarded or even utilizes your skills and talents.
It's definitely hard to make a change when you have bills to pay and need that steady paycheck. I believe that working hard does pay off. What other choice do you really have? If you want to succeed you have to work hard. That also requires the courage to make a change if you truly know the job isn't right for you.
RE: When the hard work doesn't pay off