There is a professional engineer title in the U.S. top and misrepresentating your self is illegal. However since software engineer isn’t a real type of engineering it doesnt get covered. It’s like how a medical doctor is a protected term but if you misrepresent your self as a PhD that’s not protected
All the major engineering disciplines do the same basic formulas with different concepts. Fluid flow, mass flow, electrical ‘flow’. Are all the same basic equations. Software engineers don’t need to do that, they are further away from the actual math which is what makes engineering, engineering.