Transferring video analogue signals to digital signals (such as, when transferring from VHS to DVD) has a huge, inevitable drawback: loss of video quality.
Especially, when the equipment that was used to capture the original video footage was not a high-end professional camera or a high-end VHS recorder.
But there is also loss of video quality even when the camera or the VHS recorder were high-end, because the original video footage stored in analogue equipment (such as, in a camera, or in video tapes) deteriorates over time, mostly due to heat.
This deterioration over time explains why the BAD Wembley concert (of the ‘BAD 25’ deluxe edition) does not look crisp.
Transferring from VHS to DVD is generally not a good idea when it comes to official releases - however, it is a good idea for home use in order to preserve valuable, personal video material.