Power supply IC (LDOs, converters, PMICs) power-good outputs often have weak open-drain drivers. This fact combined with the common practice of physically separating a supply from the the digital and analog processing subsystems can result in very long traces. Long traces result in large parasitic capacitances and can negatively affect signal integrity. By adding a strong push-pull CMOS driver, the signal is improved. At the same time, signals can be combined through simple logic to reduce the number of inputs required.
See more about this use case in the Logic Minute video Combining Power Good Signals.