https://www.pcgamer.com/40-percent-of-epic-games-store-users-say-they-dont-have-steam/

Epic Games said during a GDC presentation today that there are now 85 million registered users of the Epic Games Store on PC—and, according to user surveys from August 2018 and January 2019, 40 percent of them report not having Steam.

Although Valve has not recently reported the total number of Steam accounts registered, in January, the company reported 90 million active Steam users.