learning how/why things work.
In math, you learn about adding before learning about multiplication. Multiplication build on addition. You can technically learn to multiply without learning how to add, but you don't really understand it. A calculator can give you the answer, but it is still much better and more useful for you to understand without needing a calculator. Using a calculator is fine, to speed up the process, but it is a tool to do that rather than a replacement for your own understanding of basic arithmetic. Similarly in calculus, you learn about limits before you learn the power rule method of solving derivatives. The power rule makes it take so much less time, but knowing about limits helps you understand why.
What students are trying to do in many cases is try to get AI to do something they do not know how to do. If you are asked "What is 574 + 845?" in a test, it is true that a calculator will provide the correct answer much faster. However, the test is assessing your knowledge of addition. If you can't answer it without a calculator, then you don't understand addition well enough. A calculator hides that. Similarly AI can hide not understanding how to write code or write an essay.
So sure, use it as a tool to speed things up when you understand the underlying concept, but not before. There's also the danger than you could have input it into the tool incorrectly; in the previous example, if the calculator returned 1119 as the answer, if you had basic number sense you'd know immediately that it was wrong even if you don't immediately know the correct answer, and you'd know you must have put the wrong number in or asked it to do the wrong thing or something.