Because that implies you could have the display and display-contents properties have values at the same time that can conflict with each other.<p>The thing is, display: flex does control some aspects of the element it is applied to. Because there is display: inline-flex. It is roughly the equivalent of block and inline-block. It&#x27;s just an added bonus that display: flex also affects the immediate children, making them flex items to be manipulated. For instance, make a div display: table and imagine its immediate children are automatically display: table-row, or something of that nature.