however changes in absolute IQ score do not mean we are getting smarter

There is no “however”, this was covered in my sources:

“They were able to do factory work, to hunt. They could cope with the world as it existed then. They had an average IQ of 70, but they weren't all mentally retarded. So in that respect there's been no gain in intelligence”

“But if you mean: Is our ability to attack a wider range of conceptual problems improved? Then yes, we have gained in intelligence. The average person can do creative work today that they couldn't do in 1900”

IQ are good for relative comparisons between population groups, but using absolute numbers when they have been shown to creep over time by different rates depending on the type of test, disqualify them from being used to show any increase (or decrease) in intelligence

This too is covered. IQ tests are updated with the times. For this reason, people who take the IQ test just before the test is updated, appear smarter than they should be by current standards. That is to say that current populations do better on outdated tests then populations who took them when they were current. If IQ tests are sufficient for comparisons, then current populations are smarter when compared to previous populations.

Here are some problems with your source:

It doesn’t support your initial position that we should “move "Idiocracy" from parody to documentary”. Populations are still smarter than before, even if this is on the decline.

It refers to an “end of the Flynn effect in developed countries”. This was covered in my sources as well. When you contrast the developed world with the developing world, where the Flynn effect is still taking place, average human intelligence is still rising.

It states “a new study which says that our collective IQs have fallen over the last decade”. This specifically avoids statistical language of mean or median, which I would expect to be very different.

It depends on proxy studies of reflexes and assumes a strong enough correlation between reflexes and intelligence to make assertions about the latter, while neglecting the numerous other variables that could impact reflexes but not intelligence. How dumb is Stephen Hawking?