I feel like you, but your post sadly do not go enough in detail into facts that would go towards a downfall of Xbox but more on what you would want them to do/ want to do if you were in their place. So I will respond to your points and explain why none of them are good enough in my opinion on their own to be signs of Xbox going third party:
The PS3 era could have been the exact same situation, but in reverse if you have just a little bad faith. The case is not as dire now, and Xbox not being as good as Sony in making consoles is not a problem (and that can be debatable, with the One X being prefered by some compared to the PS4 pro). They knew that and planned accordingly. They have already paid the costs for this generation and leaving now would be a waste. They are profitable too, just not as much as Playstation.
Microsoft believe in Gamepass. Normal then to gain less from direct sales. This is again a choice from them. You can disagree with their strategy, as I do, but this is volontary and so should no be a problem unless theirs pland fail somewhere else, or they underestimate the loss/ the gains they want elsewere.
Gamepass is there for the long term. Them not sharing numbers is a clue that it is not as good as they want, and they have admitted as such themselves. But being slow to gain market share and not gaining enough are very different matters, so not really a problem on it's own.
The sales point and Gamepass numbers are the same story in this case: they are going up, just not good enough. As you are talking about the downfall of Xbox, and not their success compared to Sony, the PS5 domination is irrelevant as the Wii success did not made the Xbox 360 and PS3 doomed to failure, just made it harder for them to prosper. You should compare Xbox to failures like the Gamecube(beaten by the first Xbox for GOD sake) and the Wii U. Both consoles were worse failures than the Series and Nintendo did recover so no reason for Xbox not to try the same.
This is more what you want/ believe, not reality. Why Xbox was not axed after the Xbox one reveal fiasco? Because Phil Spencer convinced them to continue. He got the job close to the end of 2014. Gamepass was a thing in 2017. The gap is big enough to believe that Phil could have tried to compete without this and going another way if he wanted. Of course Microsoft want for Xbox to be profitable. They are now in for the long term. You do not try a 69 billions acquisition otherwise. And they are still trying to buy ABK so they need Xbox to do so. Xbox consumers who have a console are more easily converted to Gamepass than PC players so consoles still matters to Microsoft.
Once again, I feel the same way. As I do not own a Xbox console, had never played Xbox top games outside of a few sessions a decade ago, and do not lives in the US they have never tried to please me like Sony did. So I see their failures a lot more easily than their success. And prefer them to fail and go away than possibly harm any chances of Sony continuing to give me what I have been experiencing since the PS2, because their consoles and their exclusives are some of my best gaming memories. Xbox going third party is giving me more games to play on my PS5
But what I want/ would do is not what they want or are doing. They believe on Gamepass now. And may continue for years to try. We will see what happens at E3. Even if it is not logical, a few people have asked if Starfield would be on PS5 after the CMA rejection. I want to believe, as my PC is a 1060 and even if I do have a 3060 in a portable PC I feel that the Pc version will be shit even more than usual if Tlou part I port and Jedi fallen order 2 are any indication.
