mocha

Physics doesn't care about "accepted norms". Tea can steep well under boiling. Yes, even black tea. There are countless recipes online for sun tea that specify that the tea be steeped at ambient temperature. I think you'd be hard pressed to find a location where that gets far above 50°C.

So no, tea, even black tea, does not require near-100°C water.

I called the statement false, because it is. If it were true, sun tea would not be possible. Tea brewed at progressively lower temperatures has longer steeping time, but tea can indeed be brewed much lower than boiling point. I encourage you to test this yourself if you don't believe me.

Also, I emphasize again: I literally brew tea at 70°C all the time. So no, tea does not need to be brewed at 100°C.

This is just straight up false. I regularly brew black and herbal teas at 70-75°C (158-167°F) if I'm in a rush. It steeps long before cooling to a drinkable temperature. I haven't tried brewing green tea this way but I doubt it's much different.

Sun tea is brewed barely above ambient temperature (although that of course takes hours to steep).