Storegga might have killed 95% of all humans on Earth at the time.
Agriculture was invented in the Levant some 5,000 years before Storegga tsunami, but Dogger was a huge fertile delta system.
It would have been by far the highest yielding land at the time considering rest of Europe was still pre- the massive deforestation of middle ages.
If you look at geography of the globe, Neolithic society would have settled in Doggerland farms with large trading centres at the various river mouths.
All lost to the waves.