Valve wins by doing nothing... it's a tale as old as time.
Steam's market share is a huge factor in why their competition never succeeds, but it's hardly the only reason. Steam is a whole platform, not just a launcher or storefront. And they're also cognizant that the consumers are not just a revenue source to be milked, but actually long-term customers whose loyalty is important.
It really shouldn't be a surprise that when you enter an established market, you're not going to accomplish shit by providing a lesser service while simultaneously treating the consumer worse.