Is this a true statement? Not in Virginia.
Maybe half of the statement is correct. You can quit you job. However, you cannot always go find a better job in your same industry or locale. Why? Because of that one page document you signed 5 years ago (along with health insurance forms and who to notify in case of an emergency) which says you cannot sell the same products or contact the same customers you have dealt with for years. It is called a “non-compete” or “non-solicitation” agreement and if you violate the contract you may find yourself in court.
If you signed a non-compete or non-solicitation agreement with your employer, have the document reviewed by a lawyer who is knowledgeable in this area of contracts and employment law BEFORE you make plans to “leave and find a better job.