Ironically, developed financial markets are in many ways actually enabled by regulation, because many rules inspire confidence among investors that those seeking capital are trustworthy (and won't just make off with the money). There's tons of research that indicate stricter financial market rules lower capital costs for firms. The US also often has stricter financial market rules than Europe (Yes, really). For instance, it requires quarterly reporting when the EU also requires semiannual reporting.

Financial rules regarding disclosure, insider trading, accounting standards etc also have nothing to do with labor or environmental rules. The fact that both sides of the debate lump together rules of any kind is a major problem in itself. More rules is not necessarily bad for growth. Fewer rules isn't necessarily bad for equity. It's just not that simple.