New court documents published as part of Microsoft's defence of its Activision purchase say the PS4 sold "more than twice as many" units compared to the Xbox One. The quote reads (via GameLuster using Google Translate): "Sony has surpassed Microsoft in terms of console sales and install base, having sold more than twice as many [than] Xbox in the last generation."
Just last week, Sony stopped sharing shipment updates on its PS4 console, but the last reported figure put the last-gen system at 117.2 million units sold. It stands to reason then the Xbox One family of systems sold roughly 55 million machines, if the comment is true. Microsoft hasn't shared confirmed sales data for its hardware for years now, instead choosing to focus on player engagement and Game Pass subscriber totals.
In fact, this is something Microsoft highlights within the court documents. The company has moved "away from a strategy of 'device-centric' business towards a more consumer-centric" that allows players to access much of its first-party library through a subscription service. It concedes "PlayStation will continue to have a strong market position," however.
Shipments of the PS4 have been falling off following the introduction of the PS5 in late 2020. In the previous fiscal year, Sony shipped less than one million last-gen systems. The 117.2 million tally, however, makes it the second best-selling home console of all time, only losing out to the near 160 million sales of the PS2.
These are the same Brazilian court proceedings in which Sony claimed the Call of Duty series influences "users' console choice" and doesn't have a suitable rival. Microsoft bit back by suggesting Sony pays developers to stop them from putting their titles on Xbox Game Pass. Therefore, the company believes Sony is actively trying to stop the service from growing.