Would the complete efficiency of financial markets be desirable?

Again market efficiency means the stock prices reflect ALL the information available. In other words, you cannot “beat the market”.

Assuming you could centralize all the information available and make the market automatically reflect it, it seems to me that the financial industry as we know it would for all intents and purposes disappear: no profit to be made because the market price is the perfect price = extreme reduction in the number of companies making a living out of their best guesses for stock evolution. So it would be a huge loss in GDP for any country to implement such measures.

But suppose someone did it anyways, you would have flawless stock prices, with companies that do well rewarded for it and vice versa. They would not be rewarded as much, mind you, as in a situation like the current one, where investment firms have trillions of dollars to invest in companies that do well.

What is your opinion on the subject? This topic may drift towards more philosophical questions, such as the idea of financial markets being purely psychological phenomena.