I wouldn't be so sure. People can regurgitate from memory dialogs for entire movie series, TV shows, and countless songs. We also remember deeply nested folder structure on numerous computer systems, variety of software interfaces (e.g. click Menu > Tools > Options...), and innumerable memes/facts/lists. Sure we forget a ton (is it needle/haystack or haystack/needle?) but we know and remember a lot more than medieval epic poems.
Navigating the modern world requires an insane amount of memorization but since we no longer need to remember road signs or phone numbers, we feel we remember less today than decades or centuries ago.
- Several phone numbers
- My National Insurance number (UK version of Social Security)
- 16 digit card number for 2 cards, as well as all the other numbers on the cards.
- 10 or so passwords (less important ones are randomly generated and handled by password managers.
So as you say, we may not be able to recite a 50-page poem, but one could argue that it's a lot easier to live in the modern world with many abstract strings memorised, in addition to all the knowledge that's considered crystallised intelligence.
Now my first reaction to a popup opening as soon as I navigate to an article or a terribly illegible and busy design is to reach for the reader - guarantees one click, minimal, legible text.
In other words, if you can't trust the designers, remove the design.