What is the point of White House Counsel?

Is there any reason to still have a separate position of White House Counsel? My understanding is the position is to give the current president a lawyer to represent his own personal interests while he is president. This was needed because the Attorney General/DOJ was independent and was supposed to represent the interests of the country as a whole, which could conflict with the president’s personal interests.

But under Trump, that distinction no longer exist. He expects his Attorney Generals and the DOJ to act like his personal lawyers, and the guy who was his personal attorney (and still apparently thinks of himself as that) is now the AG. Doesn’t that make the White House Counsel superfluous? Why are taxpayers paying for another lawyer to represent Trump’s interests?