Nate is not a scammer, but was a product manager at a very successful A16Z-backed startup. He is the type of guy that was already going to be successful and wealthy, but decided to make a little more after incorrectly assuming that either (x) what he was doing wasn't illegal since he wasn't trading stocks or (y) the government wasn't looking into this type of thing. The DOJ is now disincentivizing others in his shoes from following the same path. This type of person was never going to move to a random country without extradition to straight up scam people.[0]
Your comment is akin to someone saying it's a waste of time to charge a US F500 employee or hedge fund employee with insider trading since a true scammer would just be sending phishing emails from Russia. They are different types of crimes and criminals, and I think for this type of crime/criminal, there is a deterrence effect to these cases.
And regardless of your view on NFTs, nobody was scammed here, he just front-ran to make a profit and used confidential information of his employer to do that. This is akin to a production intern for Jim Cramer buying stocks that he knows Jim will talk about on his show that evening, to profit from any short-term pump from the exposure.
[0] I don't actually know Nate or any of the details here, so I am assuming, but this is the sense I get from following this drama on Twitter.