Socialists, such as Oskar Lange, tend to treat competition as wasteful activity. Resources are spent on things like advertising and other "arms race" activities. Thus, they argue, socialism is superior to liberalism because socialism can replicate the outcomes of the market without all the wasteful competition. Given the way that competition is treated in mainstream economics, as merely a number of firms adjusting along costs until the lowest-cost provider(s) supply the market, the socialists are probably right: if the lowest-cost production technique is known, and if consumers know about the broad array of firms willing and able to supply using the lowest-cost technique, then competition is probably wasteful.
However, once we posit uncertainty and imperfect information and knowledge into the model, the socialist contention falls apart. Competition, then, becomes about information and knowledge discovery. Milgrom and Roberts' 1985 paper "Relying on the Information of Interested Parties" show that competition brings about information and allows the chooser to become fully-informed, even if they are not skeptical of all the information they receive. Don Lavoie and the Hayekians discuss how competition reveals local knowledge as well. Local knowledge is revealed not just to the producers, but to the buyers as well. Competition reveals not only what we know, but also what we don't know we know.
The key here is "competition." Without competition, that information and knowledge is not revealed. We cannot understand the information and knowledge revealed in the marketplace without understanding the competitive process through which it emerges.
One of the implications of what I said here goes to the Kirznerian point about entrepreneurial surprise. We cannot treat competition merely as a search process. We are not merely searching for information/knowledge over a known (or, at least, postulated to be stable) population. Rather, competition, by revealing new information and knowledge and changing the interpretation of existing information and knowledge fundamentally changes the population in question.