You’re right that there is a possibility of somewhat disastrous results, but in my experience it’s not the motor or high voltage electrical that goes out but a plastic part, an on-off switchbor or a sensor.
Yes be careful, you could get an electric shock photograph before you take things apart and read instructions before putting things back together.
Those aren't the only failure modes to consider for washers, dryers, and toasters. Flooding (for the first) and fire (for the other two) are concerns.