why do churches not educate illiterate workers?

You seem to be so busy looking at lavish buildings that you fail to notice the work Christians have been doing for centuries in slums. Did you not know that Baptist minister Charles C. Spurgeon risked his life helping the sick and those dying of cholera in not 1 but 2 cholera pandemics in the 1800s? That was in London, England, where only the rich had running water in their mansions, and the poor were too poor to afford basic sanitation. The Christians helped them as best they could, and they were not rich themselves! 

Same with educating the poor. Scottish Presbyterians vowed to have a school and a church in every parish, and they succeeded. They taught children with no shoes on their feet how to read and write, and then they helped clothe and feed them, and get their parents into work. You have no idea, do you?

They do all that. Perhaps your challenge is with the cost of this education. Its very reasonable but for someone who has very little it can seem like a lot. Your right, efforts should be made to make education free

Not familiar with missionary churches

or Catholic churches

are you?

Most of them incorporate real schools (especially the Catholics, they put a school with their church wherever and whenever they can afford to do so).

These are Western-style schools that, of course, emphasize things like literacy and mathematics.

Now: it's probably true that the typical worker is more interested in working than in going to school

but in that case

of course

it's not the church's fault that the workers elect to work rather than attend school.

SO: why do you imagine that churches do not educate people?

Who told you so?

Why did you believe them?

Churches have been running schools and helping to educate the poor for centuries, Ajay.  And that includes teaching hygienic practices and how to prevent illnesses, as well as the 3 Rs.

In many poor countries the churches are the only place where people can get a basic education.