I had one bad concussion that ended my skiing career. I was 12 and on a regional skiing team, had a bad crash during training and spent next 5 days in a coma. My parents were told there would be brain damage for sure, that is if I were to survive at all. It took me more than six months to rehabilitate and I was left with some double vision and severe migraines which diminished over time but had never gone away completely.
Even though I've always been mindful of my head there were a few more mild concussions over the years. I think they take a worse toll on me than they probably could have on someone without a prior history of head injury. I take longer to recover and my migraines get significantly worse for a while. I'm well aware of possible danger but going out there and riding is a conscious choice I make. Snowboarding is worth it for me.
In the end you decide whether it's worth to you personally and try to mitigate risks as much as possible. And make a living will with DNR orders if you end up a vegetable.