Unless you choose to use APIs that aren't in Windows XP, then this isn't a problem. Win32 backwards compatibility is very impressive.

Building a Win16 application would be more difficult.

But this isn't directly comparable. The issue with Linux is getting a precompiled binary to work properly across all currently up to date distributions.

You can do this even with the official Microsoft SDKs (just need to have the XP targeting pack). And then there are numerous third party development tools that allow this.

You can do this on linux too, make a chroot, done.

Windows doesn’t need a chroot and a separate install base. You can build one binary for Longhorn, using the Windows 11 SDK, and it will run on everything from NT4 to 11 without modification.

*assuming you wrote it in such a way to be able to do it

Yeah, and then hope that the tools that you need to build even run on some ancient glibc version.

Stuff like innosetup?