Is there a way to change the webbing on this picnic chair?
Looks like you can:

https://www.patioslingsite.com/products-page/chair-replacement-slings/replacement-chair-sling-1pc/

On your chairs, seems like there are caps at the tops and bottoms of the sides that you can probably slide the old sling off.

It's probably worth posting the brand here if you really want to replace them.

Good luck!