There are many coral reef systems doing quite well. The great barrier reef living system is only about 6k-8k years old. Much of that was land not too long ago.

There are many coral reef systems doing quite well. The great barrier reef living system is only about 6k-8k years old. Much of that was land not too long ago. The sea level rose there about 20k years ago (coinciding with the Last Glacial Maximum) and slowed to a near halt 6k years ago allowing coral to grow there.