I use MIDI files about 50% of the time.These are always professionally done and I always mute the melody tack. Sometimes I will sing over it,sometimes play the second verse and come in again at the bridge.
Many of them are too busy to be believable. In those cases I mute or lower other tracks and play left hand accompaniment as well.

I think they have a place in today's music as long as you are honest,and play or sing a substantial part.

Bernie