Has it? If there's one good thing about Microsoft, it's that basically anything, even from the stone age, is still supported. You can fire up some executable from the 1990s on Windows and it works and you can probably just be a .net dev for the next 50 years if you want to. If there's one company in this industry that takes long term support and backwards compatibility seriously it's Microsoft
Silverlight, Internet Explorer, Windows Phone, Microsoft Edge (Legacy), Windows Media Center, Microsoft Expression, Hotmail, MSN Messenger, Zune, Kinect, Cortana (on mobile devices), Groove Music, Windows Mobile, FrontPage, ActiveX, Visual Basic 6, Windows XP, Windows 7, Skype for Business (being replaced by Teams), Office Picture Manager, DCOM, Winforms (considered legacy), .NET Remoting (superseded by WCF), WCF itself now considered largely obsolete, Classic ASP.NET (Web Forms), etc.
While Microsoft does offer LTS for core products, they also regularly obsolete technologies, often driven by market changes or strategic shifts. Their rate of obsolescence is comparable to other major tech companies.
i mean, yes, the code still runs. but it's not useful
Last time I checked one can still choose optional MFC component of desktop development in vs installer and it will let you build old code with latest toolchain and do maintenance. Not that it makes any sense in 2024 but its still there.
ps. I've been hitting F5 every working day in vs for entire career and have no plans to switch to anything else =)