https://www.pcgamer.com/sea-of-thieves-pc-players-accounted-for-one-third-of-closed-beta/

Sea of Thieves rolled out its closed beta last month, which brought out the best and worst of the PC Gamer team. Of its 332,052 total players, developer Rare has now revealed 32.4 percent of those played on PC—which my crude arithmetic informs me sits somewhere around the 107,584 mark. 

Given this was a closed beta, accessible only via the Windows Store, that's quite a healthy portion of its overall showing.