Most people used to be illiterate a few generations ago and then only had a handful of books in the house, like the Bible and some other staples, and their letters were full of spelling mistakes, and clumsy writing and bad letter shapes. This is also seen in reddit translation requests of postcards and letters.
Your impression is based on immense selection bias. Maybe your ancestors were in the top percentiles, nobles, aristocrats, or even just doctors, academics and priests. But up until the early 20th century the vast majority were farmers and then they were factory workers.
Great writing and abundant reading was always very niche.
Selection bias means that we don't have the sheer volume of printed material that there once was, as in pulp fiction novels, not to mention the newspapers and magazines that used to be in such abundance.
Where you lived made a difference. A rural Catholic area was not what you wanted. In the city with protestant ethics, things were a little different, more than one book was permitted.
Fortunately there is a lack of aristocracy in my known ancestry, so factory workers over the last century, and reading was the thing for them, including all of the difficult books, even though none of them had much in the way of education, just basic schooling and working for Ford in ye olde factory.
Agreed that before the 1900s there were literacy issues. However, empire has always needed vast armies of clerks and record keepers, so literacy has always been important, just not for everyone.