Hi @Desleigh,
Welcome to the Bunnings Workshop community, it is fantastic to have you with us.
Having a look at your image, there is certainly some aging and discolouration, but I don't think there is anything to worry about in terms of its waterproof capabilities. Because the laminate layer remains continuous and bonded to the substrate underneath, water cannot soak through it. Moisture problems typically only occur when the laminate is physically damaged, such as through cuts, chips, swelling at joins, or unsealed edges, where water can bypass the surface barrier.
The biggest risk to your benchtop is from water lapping under the edge of the sink and finding its way into the cut ends of the benchtop. This risk can be reduced by applying a fresh bead of clear silicone around the edge of the sink to prevent water from penetrating through this seam. Check out How To Silicone a Gap for some guidance on this process.
While the risk of water penetrating the aged surface is low, you can still add some protection and restore some of the lustre of the surface by applying a very thin coating of wax or polish, such as this Glitz Beeswax Polish or Cabot's Laminate Polish. Polishes and waxes are hydrophobic in nature, and they will help to fill any microabrasions or pinholes that might be in the coating. While they are not specifically designed for this purpose, they will help to restore and protect the surface for some time until you can replace it.
Let me know what you think, and if you have further questions, please don't hesitate to ask.
Jacob
