I've heard rumours that Nvidia will be using Samsung's 5nm process, not TSMC's.
I think it's more complicated than Samsung's process node just being terrible. Ampere is a not a terrible architectural leap. It's nowhere near as good as past generations, but in and of itself it's decent enough. Availability is poor, but so is everything using TSMC's 7nm, which has been available for ages now. Power consumption is pretty bad with Ampere, but there are loads of cores, and it's not exactly miles behind RDNA2. And that high power draw clearly hasn't made the cards impossible to cool.