Software exclusivity is automatically linked to a hardware identity. It is good for development, inspires developers and creates a healthy competition in the industry. Exclusivity is everywhere in the industry, even at the level of hardware. For example, those who buy Nvidia VGA get exclusive features and this creates forward-looking competition with other manufacturers, which is actually good for users, because they can choose from several types of products. We can see how well software exclusivity still works at Nintendo today. How many consoles were sold? We can see that Sony also sticks to its own first-party titles and does not release them for everything. Those PS sales aren't that bad. MS has been forced into a business model that follows the multiplatform direction, but they still choose what to keep as exclusive games and content for how long.
Currently, the trend in the market is that multiplatform games are more profitable, but this is only because, as several people explained above, the growth of console users has decreased recently. However, don't let anyone think that if MS could sell 150 million Xboxes, they would take this direction. Interestingly, their most successful console was the one with the most exclusive games!
If they could reach the amount of hardware with which they can reach 100 million + Gamepass subscribers, they would only develop it for their own system, just like Nintendo. These are not services of love, only the current business situation dictates the direction.
And now for an analogy. You have three cars, a Porsche, a Lamborghini and a Ferrari. You love all three because they are all different and special in their own way. Each has a different engine, which has its own unique sound, dynamics and atmosphere. The driving experience is different in all three. Now imagine that the manufacturers make a decision that from now on they will only have one type of engine, the same, and from now on the manufacturers will no longer compete, they will only use this one engine because it is easier to prevail in the casual market... Where would the feeling, identity and technological competition?