I noticed this situation back in the 1990s: if a country had good black metal, any good death metal it had got overshadowed.
The prime example of this is Molested from Norway. Quality music, lost in the shuffle because... hey, it's Mayhem and they're humping Dead's corpse.
I wonder if Belial is in the same category, or maybe all later death metal, explaining why Miasma lags behind Grave on the popularity scale for reasons unknown to the gods.