Your spam info link is to Truecaller, which measures how much their users in each country get spam calls. That's definitely not a random sample of each country's users, so it's hard to say whether their conclusions are correct.
I hadn't considered the money angle before, but it makes a lot of sense. The poorest US state (Mississippi) has higher per capita disposable income than the 6th highest-ranked country (Norway). Every state other than Mississippi has a higher per capita disposable income than Australia. There are a ton of Americans, they're rich, and almost all of them speak the most popular language on the planet. The US has a high fraction of immigrants (12% of the population), so many Americans aren't immediately suspicious of accents. Compared to other countries, the US is a big juicy target.
I hadn't considered the money angle before, but it makes a lot of sense. The poorest US state (Mississippi) has higher per capita disposable income than the 6th highest-ranked country (Norway). Every state other than Mississippi has a higher per capita disposable income than Australia. There are a ton of Americans, they're rich, and almost all of them speak the most popular language on the planet. The US has a high fraction of immigrants (12% of the population), so many Americans aren't immediately suspicious of accents. Compared to other countries, the US is a big juicy target.
1. https://www.statista.com/statistics/303534/us-per-capita-dis...