JSFiddle - React, Tailwind, and code Playground

HTML

<div id="not set">
  Test
</div>
<div id="unset">
  Test
</div>
<div id="initial">
  Test
</div>
<div id="inherit">
  Test
</div>
<div id="revert">
  Test
</div>

CSS

div{
  border: 1px solid black;
}
#unset{
  display:unset;
}
#initial{
  display:initial;
}
#inherit{
  display:inherit;
}
#revert{
  display:revert; /*see https://caniuse.com/#feat=css-revert-value */
}

JavaScript

let elements = document.getElementsByTagName('div');
for(let index = elements.length - 1; index >= 0; index--)
{
  let element = elements[index];
  let style = window.getComputedStyle(element);
  let display = style.getPropertyValue('display');
  element.innerHTML = element.id + ": " + display.toString();
}