Worn carcass edges

Hi, edges of my kitchen carcasses, and also various filler/end pieces (but NOT the doors - they're fine) have become worn and grubby. Is there a fix for this? Spending £££ on new carcasses seems a lot just to refresh a tired looking cupboard - and even if I replace them, I guess I'll just get the same problem a few years down the line, right?

Grateful for any advice. Thanks.