It depends on what you mean by "better off".
What Microsoft is doing right now, by offering Call of Duty games on all platforms without any advantages, is effectively just buying Activision for their cash flows with no competitive advantage by the acquisition itself. So either Microsoft just REALLY loves the cash flow that Activision generates, or they have ulterior motives for the long-term to be able to gatekeep Activision titles on GamePass. I think the latter is true, but some people are significantly underplaying the importance of this type of move in the future, and is why the FTC has decided to file suit.
I think the Xbox platform as a whole would be BETTER OFF investing organically into their first party studios with a far lesser sum than $69B and making compelling experiences that aren't otherwise already on the market, even if they made those exclusive due to being Microsoft Game Studios titles. Gamers get more games. Xbox gets more mindshare at Game Awards and the general zeitgeist which they are sorely missing now.