This function can be very helpful and save time.
But in the end, this function is not an absolute certainty that all chords are correctly set and recognized.
I would like to try to briefly describe why this is the case.
A midifile consists of several tracks and contains a whole song and the guitars often pick up the chords.
Similar for pad, strings, organ or piano tracks.
Just as some musicians can hear what kind of chords they need to pick, software can recognize the chords from a song. Only software does not hear anything, but analyzes the chords from the note events.
The bass, melody and accompanying voices of the song are examined by recognizable chord structures and the result is displayed in the form of chords.
But as I said before, the software can't hear anything, it can only orientate itself on the note events.
And note events can also contain notes in the software that irritate the software and lead to incorrect conclusions. For example, for special effects or tracks with noise effects, etc.
Furthermore, there can be problems with jazz music pieces with alternating chords.
Alternation is used to bring more variety into the harmonious progression.
Chord elements of a corresponding chord are changed and are therefore not clearly recognizable by the software.
There are also problems with songs that mainly use melody voices and don't have a clear treble structure.
It can also cause problems if a chord contains foreign bass notes.
For example, such an Eb7/C chord could be a CM79 chord!