Because it's not a conflict of interest. It gives Trump ammo to argue to the moron MAGAts who already side with him and already believe it's fixed that this is further evidence of a fix, but this has zero to do with the case against Trump. And it gives the prosecution no advantage.
A conflict would be something like Clarence Thomas or Alito getting lavish gifts from people/entities that appear before the court and not recusing - and clearly no one gives an actual shit about that, so this one where there is no actual conflict shouldn't move the needle. Certainly a stupid move, but the folks who can't compartmentalize or think this somehow means she's bad at her actual job are either telling on themselves or aren't thinking clearly.