2019 was the year the PC gaming platform wars went from cold to hot. Steam entered the year with ~75% of the PC digital games market and roughly 90 million monthly active users — an unchallenged dominance built over 16 years. Then Epic Games Store arrived, armed with Fortnite billions, a 12% developer cut (vs Steam's 30%), and an aggressive exclusive-buying strategy. Developers cheered. Gamers raged. Steam added features it had ignored for years. The battle of 2019 set up the decade's defining platform conflict — and Steam still held the high ground going into 2020.