Sure it would get them a spot in the streaming platforms, but I’m sure MS is already making money with azure hosting those platforms.
Since they own Azure, MS can stream from it without paying anyone else a profit. This could allow them to be more competitive than Netflix can be on its own.
All of these streaming businesses need content. They are large money pits as well. Look at the spend on original content every year. What does it really drive in addition for MS ? Amazon did it as another benefit for Prime members. Google already has Youtube. Apple pushes hardware. Just curious what the net benefit for MS would be. Their xbox sells well alone, not sure if it makes a difference.
It could be argued that "because it makes money" is the only valid reason to go into a business. Certainly Microsoft can afford to buy any content at all that comes to market, just like Amazon and Netflix do. There's no special recipe here and in the age of cord cutting, consumers are extremely fickle about where they stream.
MS also has the unique experience of vast profits from Xbox Game Pass, another decision which has costs them millions in content acquisition (by buying studios) yet returned many more millions as profits from recurring monthly subscriptions. Sound familiar? This is Netflix's model, too, MS has shown they can already play that game profitably.
I wouldn't like the chances of Netflix or Spotify, MS are not a media services company and have shown repeatedly that this is not something their corporate structure can handle.