Both business owners and salary earning are both income generating activities which helps in providing the basic needs of man, what matters most is the amount of effort you put in running either someone's business or your personal business that determines the output you get at the end. Although must successful men or women are self employed people that have full knowledge of business management and control. Been self employed helps in building financial stability and control over once capital when it comes to finance management of any kind while and employee don't have such right to make financial decisions except it is approved by his or her employer.
You are right in what you said, the only difference with earning salary is that the employer controls the hours they work, furthermore, they are also no work no pay as they are employed by employers and are obliged to go to work or else they will not pay them anything.
Unlike a business owner, you are in control of your time, even if you don't go in because you have manpower in your business, you still have income to get because your business generates income for you or for us as owners.