What’s the difference between a “hidden gem” and a small mountain or beach town people forget exists and don’t move to?

Everyone wants to have moved to Asheville/Coastal FL/Steamboat Springs/whatever “before it got big”

Nobody wants to move to Wytheville, VA, Chincoteague, VA (couldn’t think of an irrelevant FL coastal town) or Craig, CO

Like, what makes Craig, CO or Wytheville, VA “quiet little white trash redneck mountain towns” (to quote South Park) while Steamboat in the 90s was a “hidden gem”