The fact remains, we have seen how a presidential election, under the current system, could be determined by 537 votes in just one state, controlled by Republicans or Democrats.
It’s much easier to commit and conceal fraud affecting as little as 537 votes that could be needed to change the outcome in a single, critical state than it would be to manufacture the hundreds of thousands or millions of votes needed to change the result of a national election.
In a scenario of obvious fraud, the federal courts would step in to keep a single corrupt city from changing the outcome of the election.
The current system may reduce the effects of fraud in safe states, but correspondingly it magnifies the effects of fraud in swing states. It’s very unlikely that corrupt elections officials in Cleveland will be able to swing enough votes to change the national popular vote, but they very well might swing enough votes to change the result in Ohio. The result is that it’s more likely fraud will decide the election under the current system.
Foreseeing apocalyptic mythical fraud as a reason for keeping a system where most people’s votes don’t count for anything is not a compelling argument.
I don't think the prospect of weeks of inspecting hanging chads in a dozen states is all that mythical. Elections are close because Americans are highly divided on several key issues. This will continue until the government runs out of money to distribute and ink to print money.