Our highchair is 6 years old and it was looking like it. Baby isn't a complainer, but I found in addition to the fabric being seriously stained, the inner batting of the cover was all balled up right in one spot that was somewhere under his right thigh.
I was making some big totes the other night with that awesome Ikea red polka-dotted laminate fabric and whipped this up too. It's got a double layer of fleece blankets also from ikea in it for a soft cushion. The whole thing cost less than $10 to recover.
Don't look closely. The stitching is NOT fabulous. But it's sturdy, comfy, and it reverses (doesn't everything?) to a brown nylon ripstop. And baby seems to like it.
(plus now it matches the kitchen... and everything else in my life!)