I used to use WiX for simple app deployments (create Programs File folder, dump assets) and Windows Services. The v3 documentation is decent for this. https://wixtoolset.org/docs/v3/ I’m not sure what development in the MSI world necessitates a radical change in how WiX functions, but apparently that is the case.

orca.exe from one of the older Win SDKs can really help with your understanding of the MSI format, which helps when building for WiX.