I think his drop off in form this season has been significant. He still has the ability to have stellar games & a 70% peak VvD is still a good player. However his level and consistency have dropped. Is it a 1 season thing or just part of his potential decline? Who knows? He is 32 at the start of next season though. Mid to long term planning to find a successor needs to happen soon.
He’s far from the only player this accusation can be pointed at. However he’s one of the few players lots of fans don’t really want to say the uncomfortable truth about based on this season’s performances as a whole.
Don't think he ever regained his top speed after the knee injury. Before that, he was at the point where almost nobody took him on in a footrace, they knew they would lose the ball. These days players know they have a chance.
Playing behind a midfield that protected the defensive line more, he could be excellent imo. Asking him to defend wide, track players high up the pitch every game, he'll get exposed more and more.
Up to us to assess his current level properly and tailor the tactics to suit.
What we have, there's still a fair bit to work with, but for a while now we haven't been making good calls imo in terms of having a plan of how the new signings fit in, how to make the best of declining older players, contract decisions. Just hope this decline in decision-making quality isn't terminal.