https://en.wikipedia.org/wiki/Portuguese_man_o%27_war#Venom
I'd say it's statistically unlikely you'd run into them, given just how much water there is on earth. And even if you did, you're going to have 30 seconds of a bad time. Sure, according to the article you could have 3 hours of pain. So a warm bubble bath treatment. Death is only found in extreme cases.
I've been in 2 car accidents coming from or going to work... and I can tell you I'm never going to earn anywhere close to $100,000,000. Work has demanded I drive through dangerous blizzard conditions many times because the business doesn't stop even though it's not safe to travel.
I'll absolutely risk maybe seeing a man o'war. Because on paper, it appears to be less dangerous (since I'll be teleported away from it 30 seconds after) than any 9-5 job.