score:6
There are two main reasons to get an IDP:
You cannot legally drive a car in a foreign country without one (eg Japan).
Rental agencies will not rent a car to you without one. Often the same set of countries as 1, but not always: for example, Malaysia no longer requires an IDP, but many agencies never got the memo and insist on one anyway.
A fake/unrecognized IDP will not qualify for reason 1, and you risk serious fines and potentially jail time for essentially driving without a license if caught by police.
For rental agencies, a convincing-looking fake IDP may well pass muster without exposing you to criminal penalties, so it could potentially be useful... except that if the T&C requires a real IDP, and you don't have one, this will invalidate any insurance. So I still wouldn't risk it.
All that said, a real IDP from the AAA costs only $20, while the fakes often cost much more -- the primary target audience seems to be people without ID at all, not tourists venturing overseas.
Here's the AAA and FTC on the topic: https://www.seattletimes.com/life/travel/aaa-warns-of-fake-international-driving-permits/