Windows as a software package would have never been affordable to individuals or local-level orgs in countries like India and Bangladesh (especially in the 2000’s) that are now powerhouses of IT. Same for many SE Asian, Eastern European, African and LatinoAmerican countries as well....
I think your third point is key, one thing Microsoft does very well is backwards compatibility. We run programs from the 90s in production. It is a nightmare of APIs layered upon APIs, but the programs will run.
Random thought: Windows is largely successful because of Piracy
Windows as a software package would have never been affordable to individuals or local-level orgs in countries like India and Bangladesh (especially in the 2000’s) that are now powerhouses of IT. Same for many SE Asian, Eastern European, African and LatinoAmerican countries as well....