Few generic switch mode power supply low current ones ? Eh, sure, there are few chips that are very popular but they're generally old and not super efficient.
Anything else ? Sure you can replace existing one but that requires redesigning the device so if you used part A but now can get only part B sure, you might get your 3.3V 5A out of it but you might need different sized capacitors/inductors, and you will certainly need a different board layout.
Even something simple as transistor used in power regulator (if it is big enough to have separate controller and transistors) might have same/higher amps but different other characteristics so you have to tweak the design a bit to get to the performance.
Simple microcontroller ? Even if any similar one on market fits the requirements, unless you get part from same family (just having more memory) you ain't fitting same code on it even if it is same architecture, the register map and their function can be different even within same family of chips, let alone different lines so you're up for the recompile at the very least, rewrite of parts at worst. And again board needs to be changed
some 5/3.3V linear one? Sure.
Few generic switch mode power supply low current ones ? Eh, sure, there are few chips that are very popular but they're generally old and not super efficient.
Anything else ? Sure you can replace existing one but that requires redesigning the device so if you used part A but now can get only part B sure, you might get your 3.3V 5A out of it but you might need different sized capacitors/inductors, and you will certainly need a different board layout.
Even something simple as transistor used in power regulator (if it is big enough to have separate controller and transistors) might have same/higher amps but different other characteristics so you have to tweak the design a bit to get to the performance.
Simple microcontroller ? Even if any similar one on market fits the requirements, unless you get part from same family (just having more memory) you ain't fitting same code on it even if it is same architecture, the register map and their function can be different even within same family of chips, let alone different lines so you're up for the recompile at the very least, rewrite of parts at worst. And again board needs to be changed