The idea of a centralized "app store" was not new. People had been complaining about Windows not having Linux-like package management since the 90s.
Similarly, the idea of web apps taking over everything was not new. Microsoft was acutely aware of that, since that was Netscape's big idea (also Java was in theory the same threat - write once, run anywhere, make Windows unimportant). Again, all in the 90s. This is the most fundamental answer as to why MS didn't do this stuff before. Not because of a lack of foresight, but because their foresight was good enough to allow them to identify it as a threat to their monopoly.
Touch screen phones/tablets I agree were less obvious predictions, but even if MS did figure that out early on, it wouldn't have changed their motivation to fight back against Netscape and Java and similar technologies.
Microsoft had an application store in Windows XP. Remember "Find applications"? They had an online store of sorts that listed programs, but nobody bought anything on it because there didn't appear to be any vendors on it, and CD-ROMs were all the rage back then.
App Stores have only really taken off as Internet speeds have sky-rocketed. That was not the case when XP was released; everyone was on dialup or barely slow ISDN if they were lucky.
Similarly, the idea of web apps taking over everything was not new. Microsoft was acutely aware of that, since that was Netscape's big idea (also Java was in theory the same threat - write once, run anywhere, make Windows unimportant). Again, all in the 90s. This is the most fundamental answer as to why MS didn't do this stuff before. Not because of a lack of foresight, but because their foresight was good enough to allow them to identify it as a threat to their monopoly.
Touch screen phones/tablets I agree were less obvious predictions, but even if MS did figure that out early on, it wouldn't have changed their motivation to fight back against Netscape and Java and similar technologies.
But now the tables have turned...