Unfortunately for that we have computers so we don't need high IQ to do more work like calculations but higher quality work (which also depends on what kind of work you're doing) and that is oftentimes not primarily related to high IQ (think of creative work)

Is that really true? That IQ is often not related to capacity to do valuable intellectual work in the modern world?

IQ measures reasoning capability, not speed of mental calculations.

I think you're right. (Did some ChatGPTing, and found this one holds).

But still, I don't believe IQ alone can improve your reasoning capability, could it? Like with proper education, and knowledge, a person with average IQ would more likely be able to see the correct patterns, and connections between ideas, than a high IQ person without the required education would.

It's like - having the proper education, trumps the meaning of having a high IQ. But, it's true, given the similar environment, I'd assume, the high IQ person would do better.

IQ doesn't improve anything, it is a measurement. You don't have good reasoning capability because you have a high IQ, you have a high IQ because you have good reasoning capability. It's also not something fixed. Your IQ will naturally vary over time due to both controllable and environmental factors, including some aspects of education.

Education is no substitute for IQ any more than IQ could be substituted for education. A high IQ individual has the potential to better utilize an education, all else being equal. Whether education or reasoning ability is more critical is very situational. In a tour guide, you definitely would prefer someone knowledgeable, in a detective you really want someone clever. At least for the moment the preferred workload distribution is generally for computers to help us with information retrieval and low level analysis which education trains us for while a human performs high level reasoning tasks which are represented by IQ.