[abnry]

Let's say ChatGPT gives you false information 50% of the time. It is still useful.

Just like it is harder to find primes numbers than verify that a number is prime, it is harder to dig up potential tidbits of information than to verify a piece of information handed to you is true.

[dinkumthinkum]

50% is still useful? A broken watch is useful in that sense as well I guess. I can only see that has useful if you don’t include efficient in the definition of useful.

[rutierut]

Like the comment said, if it's cheap (time, effort, etc) to reliably verify the answer the success rate doesn't really matter.

[brink]

Your prime number analogy doesn't hold water because the average person doesn't verify. Being wrong half the time has potential for serious damage.