Most scammers are incredibly lazy and honestly not all that competent. There's no need for them to change that if you can prey on the weak and vulnerable.

The difference between "the paper is out there" and "there's a button to do this" is quite obvious in cases like software exploits. A report of finding a vulnerability rarely leads to a massive automated exploitation campaign, but if that report also contains a proof of concept the amount of automated attacks radically increase. I believe the same is true for many other types of crime: even a mild bar to entry will prevent a significant amount of criminals from advancing their techniques.

I think the negative impact of these voice changers is much bigger than the advantage we gain as a society. Criminals will always exist, even crafty ones, but "we can't prevent crime so let's not bother trying to do anything about it" is not a great take in my opinion.