>No credible scientific evidence exists that ingesting fluoride is beneficial.

???

>Regular toothbrushing with fluoride toothpaste is the principal non‐professional intervention to prevent caries, but the caries‐preventive effect varies according to different concentrations of fluoride in toothpaste, with higher concentrations associated with increased caries control.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6398117/

Higher concentrations lead to better caries control (unless you go too high), what other evidence do you want?