Actually employees can receive salaries from the company, even if the salary he receives is lower than the others, which makes people move to work usually due to work environment factors that are already uncomfortable, for example companies put pressure so that employees are better resigns.
I think the amount of salary that can be a factor for employees to stay in the company. We don't need to be hypocritical that the amount of money is the main thing that is always looked at, without ruling out that comfort in the workplace is also very important. But let's be realistic, how many people who change jobs that pay them below the salary of their previous company? I don't think there will be many people like that.
It's different when the boss pressures his employees to resign, because in my opinion, self-esteem is also worth maintaining. That's not to say the employee can't stand the pressure, but again that's a different matter.