https://www.amacad.org/humanities-indicators/public-life/boo...
If 53% of all adults read at least one book in the last twelve months (as in 2017), it's still possible that the 33%/42% numbers could also be accurate ... but it's extremely unlikely. It would require an almost complete separation between habitual readers and non-readers, with practically nobody in between who has read books some years but not others. You only have to do that once in your entire life to shift from one column to the other. I rather suspect that the scary numbers are for relatively young adults, which is a non-representative sample of the whole, and that they're being misremembered or misrepresented as pertaining to the entire adult population.
P.S. The 53% number is still enough to make me very sad. It's bad. I'm just saying it's probably not that bad.
Who doesn’t read books in America? | The Pew Research Center
https://www.pewresearch.org/fact-tank/2021/09/21/who-doesnt-...
And the NEA offers some insights on the downward trend in reading (2007):
To Read or Not to Read | The National Endowment for the Arts
I'm inclined to agree. Do you happen to have a source though?