Minimalist design is simple in nature. It allows typography to speak and lets the design breathe, letting a few colours and limited elements direct the eye rather than competing for attention. Simple style tends to be timeless – designers keep returning to it once busier styles start to feel congested and confusing.
Simple graphic design works because it asks little of the person looking at it. It can take longer to arrive at a genuinely simple design than a busy one, but once every remaining element clearly has a purpose, the result tends to work well wherever it is used.