I chose mage because I love magic.

Honestly, being a Witcher in it of itself is cool if you could live with the cons of being a Witcher,

If I was a Witcher, I’d just enjoy the benefits like superhuman strength, speed, the senses, Signs, etc. There’s nothing forcing me to actually hunt monsters.

@Atlas D. Aeradon the issue isn't so much not having to hunt monsters as it is the fact that most of society shuns them, treating them with disdain and contempt to the point many wouldn't be able to find work doing anything else (unless you count assassins like the Cat School). A witcher might be able to settle down for a solitary life (like as a farmer maybe) but there's a reason you hardly see any witchers in other professions outside of ones that require killing.