This has to do with Microsoft trying to re-invent the wheel time after time, and consistently failing (within their own ecosystem) because they build things that contradict the desired user experience which prevents adoption. And with adoption, I mean the same kind of adoption that Docker (now OCI) has.
That is not a direct link between desktop-app sandboxing vs. microservice containers, but a comparison between doing things good enough for mass usage (Docker) vs. trying to do it 'the enterprise way' (every attempt beyond win32 so far, including COM, MSI and APPX). And it's not about their technology having bugs either (every tech does, not just MS-tech), plenty of the technical aspects are fine, but that alone is not going to drive adoption as the last few decades have shown.