I wonder, how can people compete with them? How can the unemployed who could have worked there afford to buy the products?
Sure this procedure reduces the price of the products, but this does not help people who can't find job in an anarchist society.
Um, no, lower prices do in fact help people who can't find a job. Lower prices of necessities means people can afford more luxuries. Which in turn means more jobs are available producing luxuries for the people who can now afford them.
A solution might be to reduce the number of hours worked in a week, like a 24-hour workweek.
However, most workers will not be willing to freely give up their work hours, even if the wages were higher, and that is perfectly just.
I don't know what planet you're from, but here on Earth, if you offer your employees less hours and higher wages, nobody will refuse your offer.
Also, reducing the time of the work-week might be a problem for employers, since it means paying more for formations, and it might make it harder for them to get to know competent and trustworthy employees. ie they would not do it unless some form of government forces them.
This may come as a shock to you, but most companies don't actually give a shit about getting to know their employees. If, as a result of automation or any other factors, there is less work to be done, companies will either cut workers' hours or fire some of them. No company is going to pay workers to stand around and do nothing (unless they have a government contract).
Perhaps some form of wealth redistribution will be inevitable in the future because of this problem?
Wealth redistribution isn't a problem, it's a normal and necessary aspect of trade. Wealth is distributed from consumers to producers. If you want to become wealthy in a capitalist society, you must produce things that are valuable to society (this concept is hard for governments to grasp).