For the sake of the discussion this should be the position most people should take. It's pretty unrealistic to expect Xbox to outsell PS5. To do this, they would effectively have to double their sales of this generation ~80M. I'm not necessarily sure if that is their goal or what not.
The real question is whether they will have a better performing generation than this generation. Do we expect them to do better than the 40~50M units by the end of this generation.
Good to remember how optimistic MS was when they introduced the X1. I distinctly recall talk of hundreds of millions of units, because it would go beyond the console, with the TV integration -- TV, TV, TV!. They thought it was the mythical key to winning the living room.
It turned out that especially for younger generations, they mainly cared to watch video and game on their phones, not sit in front of the big screen.
Maybe MS has more modest expectations, though looks like they went more aggressively towards being the performance leader this time around.
But they could start with winning the US and UK and a few other select markets.
No point in competing in this business if you're not aiming to win the market share battle.