Old laws are often superseded or modified by newer legislation that's not novel or rare. This one wasn't because it hadn't been so roundly abused by previous presidents that it had been an issue worth taking up. It's the same with a lot of delegated powers, the flexibility and decreased response time is good when it's constrained by norms and the idea of independent agencies but a terrible idea when the supreme court has been slowly packed with little king makers in waiting wanting to invest all executive power in the President. [0]

[0] Unless that's power over the money (ie Federal Reserve) because that's a special and unique institution. (ie: they know giving the president the power over the money printer would be disastrous and they want to be racist and rich not racist and poor.)