Is it true if you don’t dye your hair you don’t need protein?

I haven’t dyed my hair in years… but the dove intensive repair shampoo & conditioner makes my hair look so shiny and nice (switched to this line the last few months). My hair gets oily easily, so I shampoo almost every day. It’s also slightly wavy and always frizzy, no matter if I brush it or don’t brush it… Recommendations for alternatives if I should stop using it?