(These threads seem to need this said perpetually: nobody is claiming that you can drink a glass of fluoride and be perfectly fine. It’s all about dosage and uptake.)
1. The main dietary source of extra fluoride for most people is tea.
2. There’s strong evidence that adults don’t experience detrimental effects from much higher proportions of dietary fluoride — even the most recent skeptic fodder (the NTP manuscript) finds no effect on adults at concentrations an order of magnitude greater than municipal fluoridation can provide.
Put together, it’s unlikely that the demographics most susceptible to higher doses of dietary fluoride (meaning children) are receiving those doses. But if you’re worried about your dietary fluoride intake as an adult, you should consider not drinking tea.