Hi Alexis - I’m so glad you found value in my video! To address your specific question - MIDI and MusicXML export different types of data. MIDI is designed for music playback, while MusicXML is designed for notation. MIDI data contains note pitches, positions and velocities. It doesn’t contain any audio data on its own like an MP3, and thus requires virtual instruments to play back the MIDI information to create sound. MusicXML is designed to capture the specific formatting of sheet music, such as clefs, note pitches, musical symbols, lyrics, etc. If you’re exporting from Cubase to Dorico, you will most likely want to export MIDI to capture what is shown in your key editor. In order to export MusicXML from Cubase, you have to use the Cubase Score Editor to get a sheet music view, and it’s that sheet music that Cubase is exporting rather than the MIDI notes. Personally, I find the Cubase Score Editor to be really frustrating to use, and I find that it’s easier to get workable music going straight from MIDI to Dorico rather than having an intermediate step of Cubase MIDI > Cubase Score Editor > Dorico. For me, the primary advantage to using the MusicXML export is that you can use it to export chord symbols, which MIDI exports do not capture.
I hope that helps!