Well, to put it simply- they started to drink tea because they didn't have much coffee.
Tea is a stimulating drink and in most cultures there has traditionally been some stimulating beverage that helps people start or get through their day.
Why the Brits drank more tea and not coffee comes down to what was available and affordable to them. Other European countries had easy and affordable coffee through their trading routes, while tea was much more affordable for the British than coffee from their colonies and trading partners.
It’s hard to beat the flavour of a properly brewed English Breakfast tea with just the right amount of milk.飘着清香的英国早餐茶加入适量的牛奶，那味道令人难以抗拒。
I reckon tea has indirectly powered quite a few household products, through me turning tea into code :)
I'm finding this answer difficult to put into words , it's like asking why you like oxygen and water so much ! It's literally that important to our way of life . A cup of tea is just a little piece of heaven in a cup .