Backwards compatibility - they're definitely good at it, but I'm not sure how much money it makes them. People get Game Pass to play the latest games, and the X360 and OG XB games are just a nice to have. Yeah, Windows runs on some old-ass hardware, but there's shots fired in Windows 11 - TPM2.0 or fuck off, no W11 for YUO!

The other products copying thing - you sure? Their big moneyspinner is Windows and services built on Windows, like Azure. And whilst Windows has got roots in VMS, it's not that similar, especially once you step outside the kernel itself. Office is mostly home-grown (and they make an absolute fuckload out of 365, btw) although they did buy PowerPoint.

Lock-in - yeah but nah but yeah but nah. I know what you're driving at, but I honestly think you're only as locked-in as you want to be, in 2021. Ten years ago this was an absolute given, but things have moved on. There are whole businesses running on Google Docs now, frinstance.

You don't have to guess at what makes MS's money. You can just go look.

https://www.microsoft.com/en-us/Investor/earnings/FY-2021-Q4/press-release-webcast

(Aside: Azure is up 46%. That's only 46%. You know you're in bizarro-world when 46% growth is the lowest it's ever been, and thus a disappointment)