Think about if a regulator looks the other way, he is seen as incompetent - many times you'll not be punished for incompetence at work. But this benefits the corporate player and he can offer benefits to the regulator like private jet (for his family/friend use), maybe access to a resort where the regulator's family can stay during vacation or maybe an apartment in some posh locality where the regulator's kid can study abroad.

People are acting in their self interest.

You've salary and ethics Vs luxuries and loyality from the rich man who is unlikely to go bust.

Thing is you can choose to not coperate but that only increases the price and the rich man goes for your boss then you get in trouble as boss is cooperating with them and he may fire you.

I once dated a very rich and powerful lady in Asia and she could solve all problems with just 1 phone call - that was amazing, she new everyone everywhere it felt.