Genre would play a part too, RTS is still big on PC but Survival titles are another level on PC...They always seem to hit it big no matter what, Lol. I'm not sure why it happens but it seems as though PC fans are always drawn towards Survival titles in large numbers. Forza Horizon 5 is beating it slightly, fair to say that Forza Horizon has overtaken almost every Xbox IP in popularity though, Lol.
Sea of Thieves though...It's still going strong after 5 years on the market, 48k in one market, 5 years after launch is impressive, alongside beating Forza Horizon 5 (by almost double) and Age of Empires IV despite them both being a lot more recent to market. Plus Sea of Thieves has already done 5m sales on Steam, Lol.
I can't remember when Rare said it exactly, I think it was before the PC launch, I think they said that the Game Pass/Sale split at the time was near 50/50. The player base is now 30m and the split is 54% in favour of Xbox, so that'd be 16.2m players roughly on Xbox. Has to be over 10m sales at this point, I'd not be surprised if it's closer to 15m than 10m considering nobody on PC seems to want to use Windows Store, Lol.