It is mathematically worth it for the client, but only in the same way that car insurance is. It's a gamble on financial security. If you never claim on your car insurance then you can say it hasn't been worth you having it cause it was money spent with no return. If you frequently smash cars, then you will benefit, unless Moh.
Those under 30 GENERALLY subsidise the older health insurance clients who are more frequent visitors to medical establishments. These are the people insurance companies lose money on, but the gap (pun) is made up by those who don't claim as much. Premiums are also used to balance this.
Basic hospital cover is good because if you need a hospital it gets you off the public waiting list and can save you thousands. The other levels of cover you need to decide yourself if you're susceptible to injuries and diseases and blah blah - that's life, it's random.