It isnt a fault or a feature, it is just realistically what high end graphics cards have nowadays. Some are worse than others, akin to DSE on a LCD TV. I've seen probably 8 different PS5s between all my friends and all have had coil whine.
I'd agree that it's always there at some level, mostly unnoticeable to the average ear. When it gets bad enough to be noticeable I would consider that a fault. Especially if their are DIY instructions to fix or dampen it.