> Someone with an Indian accent and really bad phone connection calls
People are used to this when getting a call from a call center. They imagine the IRS being the kind of behemoth that might need to outsource to a large call center.
> tells you they are from the IRS
It's not inherently apparent that the IRS would never call someone. Although the IRS would rather use mail which can be certified and better archived, it's not apparent that recorded calls couldn't do the same thing.
See: https://xkcd.com/1053/
> you need to pay them "taxes" with an Apple gift card
If you're not up to date on "fancy new things happening with banking" and you're the kind of person who only ever uses checks and thinks your debit card is a credit card because of the Visa logo maybe this is just legitimate enough to trick you. Assuming the person fell for the first two aspects of this, they're probably flummoxed, thinking the "big bad IRS" is trying to go after them and want to resolve it with zero friction, so you're easily influenced. These used to be prepaid debit cards until crackdowns on Moneypak cards used for scams, maybe the person says "Get the prepaid debit card with the Apple symbol on it".
>I guess a fool and their money are soon parted, but this is a pretty unbelievable level of gullibility.
It's not being a fool, these scams target vulnerable people. Often times fear of being shamed the way your post does only furthers the harm as people stay in denial they're being scammed so they can avoid that shame.