You're getting snark because your own snarky comment is the equivalent of saying "Why do I need Make to run it on the MacOS?" If you had asked instead, "What is cargo, and how do I install it?" you would get more helpful responses. Snark is met with snark.
And how people are supposed to know that it is a programming tool? I assumed that it is yet another package manager and googling about cargo brings results about logistics.
It took me a few tries before figuring it out. What worked was "Install cargo MacOS" and it was hard to tell if the results are not a scam to make me install some spyware.
I figured it out.
It can be found here: https://doc.rust-lang.org/cargo/getting-started/installation...
You can install it easily by running this: curl https://sh.rustup.rs -sSf | sh