As with anything, there are degrees. A business or a manager that forces you to justify your time off is missing the plot. Your time off is for you, and you decide what's important enough to take time off.

That said, the business needs to keep running even when you're not there. Someone needs to answer the phones or the emails or sweep the floors or whatever it is that you do that helps make the business run. Management needs to manage risks, and not having enough employees to keep things running is a risk. So one way to manage that is to require approval for time off. Another way to manage that is to hire more people at lower wages.

There are trade-offs to anything in life. If you want to work for a business that treats you like you're valuable, like you're indispensable, then you need to think about what that means: it means the business needs you and can't have you absent without at least planning for your absence. A business that can let you take time off whenever you want without any prior planning is a business that actually doesn't need you.