Dude I work as a dev at a "smaller" company and its not bad at all. There will be bad bosses and toxic co workers, it happens, but you can always leave and find better if you need to. Usually if someone is this toxic everyone usually says something to management and that person is moved to another position or let go if they are this much of problem. Also manga is often overly dramatic because it makes for interesting stories, not many people want to read about someones productive day that has little to no conflict.
Don't be afraid it is a case to case basis. The settings of the story is in Korea so it might be different to your country.
Its different in everyone. Unless you'll be working with toxic co workers, everything is fine.
I know this is just manhwa but after reading this I don't want to work in a company.