Obviously the internet loved claiming Vega was a failure but I am pretty sure AMD actually did pretty well financially with it.
We'll never know one way or the other, there was speculation that AMD lost money on every Vega they sold, and that was long before the same speculation cropped up about radeon vii. Fury x was meant to be a total bust in terms of sales which probably goes hand in hand with seemingly not that many of them being produced due to an (alleged) very high number of failures assembling the HBM package. And the pump whine didn't help things either.
Fury x seemed more like a product produced in low numbers just to show off what size a card could be made with hbm and not much more. A pity as it was an interesting card with some of the materials used on it like the soft touch shroud plates.