Someone posted a lengthy podcast about how many kids are taught to read badly. https://features.apmreports.org/sold-a-story/
There was another article a couple weeks ago that said less than half of us adults can read at a 6th grade level. 6th grade is before you really get into metaphor and subtext. That's just reading for plot.
Some people legitimately might be bad at reading.
The people on text based sites are probably better than a whole chunk of people that don't even post.