Yep. IQ had extremely limited value, telling you basically how quickly you learn compared to others.
I used to work with adults with cognitive and developmental disabilities -my wife did too and for example she taught them Shakespeare. They were capable of learning and did. I saw discussions that showed they understood and found it interesting (more than I find Shakespeare interesting even hehe).
I happen to have a decently high IQ but I can tell you very much personally it doesn't lead to success in life. Lol
The ADHD didn't help either though. Heh