I don't even know what you're complaining about at this point, this whole comment chain is talking about organizations switching between Windows/MS Office and Linux/LibreOffice. That's a user specific situation. Developers can already build their applications on whatever platform they want. There's almost zero windows desktop required development for business purposes these days unless you're producing a video game, and even then 95% of the developers have nothing to do with OS specific code. Everything else is a web app. If you're still trying to maintain legacy code in a desktop application, that's a you problem, not a Microsoft problem.
It's also funny that you think rolling your own servers is going to be more secure than using Microsoft's (or another cloud provider) at this point. Security through obscurity has never been a good idea, and AI has made that strategy 1000x worse.
I think you're too far removed from the jobs regular people, if they sit in front of a computer all day. They are spending their time in Outlook, Excel, Word, PPT, and they may have one dedicated line of business application for finance, HR, or similar. Especially in governments (as per what this comment chain is about)