Starting a business is a winnowing process — only the fittest survive.
Tips
usage
Often used at the end of a sentence as a stand-alone metaphor, or as an attributive: 大浪淘沙的过程/考验. Describes markets, history, competitions — anywhere harsh conditions select for quality.
culture
Also the title of a 1977 Chinese film 《大浪淘沙》 about young revolutionaries in 1920s Guangzhou, and the name of several TV dramas. The phrase carries connotations of historical reckoning, not just competitive filtering.