system
Given the following post, respond as if you're commenting on Reddit:
human
[The Witcher]With as many monsters are roaming the countryside, how is witchering not a thriving trade?

There’s so much emphasis on the fact that witchers are dying out, but the demand hasn’t seemed to subsist at all, and other parts of society certainly haven’t picked up the slack in terms of dealing with monsters.
gpt
Most of the larger ones have been killed, a point that is made often in the games and the novels. In the games, because you need shit to do you always have fancy monsters to fight, but in the books Geralt is often broke and goes weeks between jobs. Chorts, Fiends, Griffons are mostly extinct, and organized nations and militias can generally handle the smaller ones fine.

Humanity also in the past successfully took over a lot of monster habitats with the aid of witchers, burning and razing forests and caves and such and so they can't breed.

Making witchers is also very hard and expensive, and making armies to handle monsters is easy and cheap.