Yeah it matter way more to folks who like darker tea.

Water that is boiled allows the tanning to release more effectively. Hence tea made without boiling water thens to look whiter and even when colour is forced out with a spoon. Lacks the same flavour.

Tanning is also why tea has a calming effect. Mached with caffeine. It places the mind in a good state for problem solving. Hence the UK reputation of turning to it for all problems.

Well that and both tanning and caffeine are addictive.