Again, shout-out to little Sea of Thieves over there. 6 years later and still outselling plenty of "system-sellers" and "Must haves".

Sea of Thieves isn't in the top 20 YTD for 2023 lol. 

Okay... and? That doesn't change the fact that, on September 2023 (5 years after its release) it outsold plenty of games that are:

a) Much more recent (as recent as last year)
b) Regarded as "system sellers" and "must-haves" by the media
c) Not included on a subscription service since day one

Games such as FH5, GoW:Ragnarok, Cyberpunk 2077, HFW, Ratchet & Clank, Diablo IV, FFVII:RE, TLOU2, GoT, etc, etc, etc, just to name a few examples.

Sea of Thieves barely charting for one month is not impressive. You also said "still outselling" in your original post, which is a different framework than Sept 2023, and is factually wrong on top of that.

I mean, whether you think it's impressive or not is irrelevant; that doesn't change the fact that it outsold them all.

People had the chance to play Sea of Thieves for free and they still preferred to pay for it instead of one of the other "bangers". Obviously SoT became a "must have" for those people.

How does any of this dismiss your claim that Sea of Thieves is "still outselling" must haves and system sellers? Sea of Thieves outselling them for one month is not the same as consistently outselling as you implied. 

Sea of Thieves is probably the 2nd biggest original (pre acquisitions) Xbox game after FH5. Its sales performance is definitely impressive for an IP that no one took that seriously at launch. But it is a popular GaaS title, and these usually get sales spikes with updates, in this case Legend of Monkey Island Tales 2 and 3.

Starfield boosted XBox sales, but not enough to put it above PS5 for even one month. The game was unquestionably a huge release. It seems like it is helping the PC a lot more than the XBox console though. Considering both of those are Microsoft platforms, that might actually be part of their plan.

I have always said that Microsoft made a big mistake when they decided to release their games on Xbox and PC simultaneously. I think a lot of people want to play Microsoft's games, they just don't feel the need to get an Xbox for it. That becomes evident when you compare Microsoft and Sony's games on PC. The relatively weak Sony's games numbers show that people buy Sony's console to play those games, whereas a lot of people are just comfortable playing Microsoft's games on PC.

I think they would still reap the benefits of the PC market (without hurting their console's sales) if they released their games at least 6 months later on PC.