They can afford to educate their own line and hoard resources across generations doing so. They can fail as many times as it takes before they finally succeed because of this. They throw the bodies of the world at their problems until they are solved, which necessitates an uneducated populace that doesn't realize they're chattel and canon fodder to this purpose. A populace that fear collective power, that fears community beyond immediate family, that shies away from actions that would better the world in favor of actions that are less risky personally.
Elites are always worried about the labor crisis - “nobody wants to work”. Usually this is about blue collar work, and their desire to underpay and overwork service/laborers.
Globally, this class of people definitely wants to reduce literacy to keep a stream of manual labor inflowing.
The number of vastly unequal societies throughout history who have banned the lower classes from learning how to read, or from any kind of education at all - beyond whatever narrow training will make them better perform their specific duties for those on top.
...and not just historically. Some societies where significant minority groups are banned from getting an education, in order to further perpetuate their marginalisation, still exist today.
The response to your comment thread here is some pretty high flying conspiracies. The thought that those in power would try and make the country illiterate is straight up ridiculous. That would completely undermine the competitiveness of the country AND the time line to get any benefit for the "elites or whomever is behind it" would be significantly long.
Now if you are talking about a country like India - sure I could see Modi doing that. In that case it would be more about restricting growth and investment into education then dismantling an economy built on knowledge.
I don't think I said anything about making people illiterate.
Undermining literacy means so they are not as literate as they could be to improve their lives.
For example, there are more than a few studies on literacy and education levels of the political spectrum for better and worse.
India is a different world. The crime against humanity that is the caste system all but forbade 1-3% of the population to be permitted to learn how to read. 95-98% of Indians were not permitted to learn how to read, and had to rely on the interpretations of the less populous castes.
Ironically it is a minority that largely broke this logjam and helped push literacy for the many forward.
I'll gladly take the downvotes for speaking the truth about caste being a divider between people and society.