Except if you drink the daily recommended amount of water, you don't come anywhere close to the fluoride in 1 cup of green tea. It's just a completely delusional panic.
What figures can you point to on mg/L of fluoride in (commonly consumed) green tea vs tap water?
Even aside from that, it’s a specious argument: people who want to avoid fluoride can just avoid green tea; it’s much harder to avoid it in tap water.
As for “delusional panic”: it matters a lot for iodine absorption and thyroid function for some people, which is a both widespread and overlooked/diminished, at great harm and cost to those who are affected and unable to get help.
For what it’s worth I’m not advocating for removal of fluoride from tap water, but there does need to be more recognition of the harms to those affected and serious efforts made to develop treatment approaches for those with iodine deficiencies and thyroid dysfunction, as it really is a catastrophic problem for a lot of people.
Municipal tap water in the US is fluoridated between 0.7mg/L and 1.2mg/L, per the CDC's 1962 guidelines[1]. To my knowledge, most municipalities choose the lower end of that range (since the effects are diminishing and, well, it's cheaper).
By contrast, at least one survey of black tea infusions finds an average of 2.65mg/L[2]. So over twice the CDC's highest baseline for municipal fluoridation.
(Note: at that average for black tea, an adult would still need to drink ~4L of black tea a day to pass the CDC's tolerable upper limit. People grossly overestimate both how much fluoride is dangerous, and how much they actually consume.)
https://pubmed.ncbi.nlm.nih.gov/34343066/
General discussion: https://en.wikipedia.org/wiki/Health_effects_of_tea#Fluoride...