Frenkie has consistently been one of our better players until this season. Hardly flopped since leaving Ajax.
De Ligt has had to battle with Chiellini and Bonucci for a starting spot whilst suffering injuries and similarly to Frenkie a woeful management of the squad and managers.
Ziyech is now getting much more game time at Chelsea.
They're not flops, for Frenkie/De Ligt they've had average managers at the helm and terrible squad investment (if at all). Ziyech just needed time to settle. VDB was managed by Ole who won't manage a top half of the prem team for the rest of his career.