It depends what the pillow is stuffed with. There is one pillow in my sectional that is stuffed with Polyfil (or something like it) instead of foam, like the others. So I get the Polyfil like stuffing at Walmart and re stuff it when it gets flat. If the pillow zips open, I’d unzip it and see what’s inside.
Could it fit a foam replacement instead? That would hold up better over time
I agree that stuffing it with foam might work, too.