As long as there is not a monopoly, privatization and free market capitalism is one of the most beneficial sources in all the world. Responsible for most of the modern advances in medicine, technology, and making these things available to the widest amount of people throughout the world.
It naturally makes everything more affordable. Because there is competition between multiple companies, they are encouraged to lower their prices. Because if one company lowers the price, the other ones would go out of business. So all of them end up lowering their prices, and the product is now available and affordable for the most amount of people.
It also encourages invention, new better designs, and efficiency. Companies are encouraged to make higher quality products, and invent new better designs, because then more people will buy from them instead of the other companies. They also are encouraged to invent new ways to produce products more efficiently with less waste and less pollution, because when they waste less materials, they can build more product and make more money.
Nationalization has the opposite effects. Because they don't need to think of a smart way to do anything, because the government will always bail them out and give them more money. So they can fail horribly in every way, and the government will waste endless money keeping them alive. Why be efficient with the way you use your materials when the government gives you endless materials? Why invent a better design when everybody is forced to buy the low quality design you have because there are no alternatives?
Nearly all medicines in the entire world are invented in America. Because the American medical industry is made of private companies which each have money to spend on researching and developing new medicines. And if they succeed, they make their money back and make a profit. This gives them the flexibility to take more risks and work on designs that are more difficult. 
The best example I can think of comparing privitization with nationalization is the US Postal Service. The US Postal Service is total garbage. It works pretty well, but it has it's problems and it's just not sustainable. Every single year, the US Postal Service falls into Billions of dollars worth of debt, and every single year the government pays off this debt for them. Without the government keeping it on life support every year, it would not survive even 6 months. But at the same time, we have the private companies like UPS and Fedex that are very highly profitable and successful. Because they compete with each other on having better service, they compete with each other on having better prices. And this refines them into becoming better quality, more efficient, and lower priced. Because they have to be to survive. Each company has to find a way to get the package to its destination in the fastest and safest way, for the least amount of money. A nationalized company doesn't need to worry about that kind of quality. It will get there whenever it gets there, and it might be damaged, and we don't care because we're your only option and you have to keep being our customer.
When there is an endless supply of money coming in, regardless of work or performance, people get lazy. They don't need to do a good job, they don't even need to do anything. They are going to keep getting paid no matter what. And they're only going to get paid more and more every year. Because the government is always there to pay their debt for them. And whatever inefficiencies and problems there are now, they only multiply every year. Because it's a guaranteed check coming to them. Actually they are encouraged to purposefully be more inefficient and more wasteful. Because if we do not use up our entire budget for this year, they will give us a smaller budget next year. So we need to waste at least as much money this year as we did last year, and we should actually waste even more after that so they'll give us an even bigger budget the year after.
Free Market Capitalism is what brought the quality of life over most of this planet up to the highest levels in history. Because it is the creator of technology, advancements, and it is the force which makes these technologies less expensive and able to be shared with more people for less money.