I use similar as one ingredient in a mix, never as a carrier on its own as I think it is too rich for that especially in still water. The cat food can be stodgy if not diluted with something else. My idea of groundbait is to attract rather than feed. The feed comes from particles added to the groundbait carrier. A lot of cheap pet food is made up of vegetable protein and I don't think that is as attractive to fish as animal protein. Chicken layers pellets or trout pellets might have half the protein content as cat food, but it is animal protein and better in my opinion.
Dependent on the swim I'm intending to fish I will soak some groundbait overnight so it can be mushed up the next morning. This can include milled wheat and maize, soya powder, molasses and chicken pellets. Living on a farm I can get industrial quantities of milled grains, molasses and soya powder free gratis. There are two 20 tonned hoppers of wheat and maize and a 1000 litre tank of molasses virtually outside my front door. Milled wheat and maize makes a great groundbait base if soaked in hot water overnight.
I try to make the groundbait as light and fluffy as possible given that it might have to be catapulted out and carry particles. If I don't use molasses I'll sometimes add flavouring from supermarket cake baking products; vanilla mainly for roach & bream, or sometimes strawberry for carp.