A friend of mine is a project manager at AMC movies. Her job is managing promotional the development of products, events, promotional materials, etc. There were 4-5 of these managers for the whole company and they were assigned the projects. It took 2-6 months for any one project. As a single mother of two she was working about 50 hours a week, which meant evenings and weekends. Back in 2017 or so one of the project managers left for maternity and soon after another quit. So the company reassigned the jobs, and expected the deadlines to be met. Suddenly she was working 70+ hours a week, working late into the night, not sleeping enough, and highly stressed. The other pm were in the same boat and one of the others was thinking about quitting too. The company thought they could save the salary of replacements and expected the work to get done, no extra pay mind you. My friend couldn't quit but she started looking for a new job. When the higher ups found out they faced a mass walkout they agreed to hire more managers.
I was stunned that the higher ups couldn't understand that demanding 3 people do the work of 5 was reasonable.