I think operating at 5V input might be a technical constraint for them. Compatibility revisions for existing hardware are a lot more difficult if the input voltage is 9x higher. Addressing that isn’t as easy as slapping a buck converter on the board.
Not saying requiring 5A was the right call, just that I can see reasons for not using USB-PD.
We are not talking about 9 times higher. 3A at 9V would be enough.
I am currently looking in the Docs and it is really confusing. It states that the PI 5 has a PMIC on board but still saying it boots up only when the 5A is present… So not sure what is going on here.
And looking at the PD 3.1 standard it looks like 5V 5A is actually in the spec in the new Version…
Will have to get my hands on the new PD 3.1 spec.
