When Oliver Twist was published (1838), a third of the British population couldn't read[1].

[1] https://www1.umassd.edu/ir/resources/laboreducation/literacy...

14 percent of adult Americans demonstrated a “below basic” literacy level in 2003, and 29 percent exhibited a “basic” reading level.

That is with public education.

> Dickens was the most popular entertainer of his time. Shakespeare was widely popular as well. Both are considered too difficult for most audiences now days.

Difficult largely because of the relatively rapid rate of drift in English idiom (which is a unique feature of English); but less popular largely not because of difficulty but drift in taste for entertainment media which is more about shifting fashion than any issue with capacity.

I think you are disregarding the degradation of the human attention span that modern media has brought to our minds. If you really think there is no difference in capacity between the minds of that time and now, just google "technology and attention span" and spend some time with the results. If you can manage to hold your attention long enough to read through them :) I know hardly anyone anymore who can sit on a couch and read for even 5 minutes without a break in attention to do something on their phone. The capacity absolutely is not there.

Dickens was serialized - there was only so long you could spend reading new Dickens before you ran out of it. (I haven't been able to find the typical length of a portion, though.)

On the other hand, plenty of people will spend a weekend on the new Harry Potter.

32 pages. <http://dickens.wpi.edu/history.html>

> I know hardly anyone anymore who can sit on a couch and read for even 5 minutes without a break in attention to do something on their phone.

I definitely don't align with this sentiment, sounds more like who you are surrounding yourself with. Many of my friends and coworkers are avid readers, and books are a common discussion topic.

There is also a flip side to how technology has affected our attention span. Consider how many people now "read" while driving, working out, doing chores. Yes we may crave more stimulation, but it means while doing laundry or dishes we are going to seek out audiobooks and podcasts. I read more than ever now that I can get just about any book instantly, and read on the go