system
Given the following post, respond as if you're commenting on Reddit:
human
[Witcher 3] What happened to all the Witchers? How many are left?
gpt
The experiments that led to the creation of Witchers were stopped and most of the Witchers died doing their job, monster hunting.

As for how many are left maybe a dozen? There are tales of The White Wolf working with and against other Witchers, but they've become less and less frequent as the years go by.