I'm going to link my favorite survey [0] to illustrate this point. Its called the PIAAC, and it's a internationally standardized assessment of adult skills in literacy, numeracy, and problem solving.

28% of the US is at Level 1 or below. That level roughly corresponds to reading a simple text and being able to answer a question about it that requires limited inference (i.e. if the question is "what color are pigs," the answer would be in the text as "pigs are pink in color.")

[0]: https://nces.ed.gov/surveys/piaac/2023/national_results.asp