
In reality, it is bad.
I also watched a videos of a reporter who uses this as title. Japanese men are overworking and some are even sleeping on train, on pathways on their way home. She even uses white tape to mark where the japanese men are sleeping due to overwork.
It also featured the reason why they overwork.

Despite being one of the most technologically and economically developed countries, Japan is an extremely oppressive country to live in. Suicide rates are staggering. They have many "black companies" (exploitative employment systems) and it's not uncommon for Japanese workers to die from overwork. Japanese are also highly sexually oppressed. There are more sex services in Japan than there are public bathrooms and you can tell by the weak women and the sexual nature of most manga depictions there are underlying societal issues. People often complain about the "groped on the train and didn't put up a fight" trope in Japanese comics but it is actually very common since Japanese women are so oppressed they feel like they can't even stand up to gropers, they don't even make a sound. That's why they introduced "women only trains" in Japan to deal with the groping problem. Sorry for rambling. I just feel passionately about the issue. What we consider to be "developed nations" by Eurocentric standards I feel needs to be criticised more often.

You're right, they are not even treated as people. Japan is a society deeply rooted in military culture, so Japanese workers are seen like assets and tools of efficiency and productivity. They are taught to be tools from a young age. Even the black school uniform with the collar that Japanese school boys wear is actually a military uniform. The stiff randoseru backpack that elementary school children wear to school was originally used for the military as well. No one can talk back to their teachers, bosses, and social hierarchy is very strong because everything is structured after the military...
Is the stress level of japanese sales man that bad?