Because it seems like this is a major and obvious flaw that is relatively easy to fix in a lot of different ways… yet it shipped.
It’s easy to just say that Microsft’s developers are incompetent/dumb/etc but this is low hanging fruit, and makes me think the problem is something else.
Voice Recorder is pretty old, it got a big revamp/renaming ("Sound Recorder") in Windows 11. Problems might be fixed now?
The native development story on Windows is in shambles. UWP and WinRT have a ton of baggage but there isn't a great replacement for them yet. Many bundled apps were written in UWP when it seemed like it was the future, and now they're in an awkward not-quite-unmaintained place.
I see the trace is spending a lot of time in the Windows.Storage.* namespace and... there be dragons. Filesystem access from UWP apps is awful, it has several usability and performance shortcomings. Would not surprise me if that's a platform issue and not a Voice Recorder issue.
There is, in fact, a new sound recorder app on W11: https://www.pcmag.com/news/first-look-windows-11s-new-sound-....