Crowns arrived on beds long before they arrived on furniture generally, and they arrived for a specific reason: the state bed was where a ruler received visitors, so the bed had to say something before anyone spoke. The coronet above the headboard did that work. It became decorative only after it stopped being literal.
What makes it hard to carve is that a crown is mostly air. The band is solid, but the arches rising from it enclose empty space, and every one of them has to be cut through and shaped in the round while staying strong enough to survive a house move. A carver who rushes it leaves the arches thick and the crown looks heavy; cut too fine and it will not last.
Our master Indian artisans work the coronet from a single block, hollowing between the arches from both sides so the openings are clean through. It is gilded afterwards, never before, so the gold follows the finished form rather than filling the tool marks - which is the difference you see when a lamp is on and the arches throw real shadows onto the wall behind.