Why is IRR an important metric for comparing investments if CAGR can be determined?
I understand CAGR to mean the constant rate of compounded growth over a given number of years. That is, the slope of a straight line drawn from the beginning to ending values over time. And I understand IRR to mean the discount rate at which the NPV is $0, based on the specific cash flows of a project.
If those intuitions are correct, and the basic goal is to grow money as much as possible over a given period, how did IRR come to be the more predominant metric? Essentially, why care about the IRR at all if you can know or estimate the CAGR of two investments?
Thanks in advance.