Why does saree reveal belly? Why indians been wearing it for so long? Is T-shirt better?

Answer :-

Opinion 1:-

Why does saree reveal belly?
Because of the way it is worn. And it depends on the blouse one wears. One may also choose to wear a blouse that goes down till the waist to cover the belly completely...like so...
Or one may wear it the way a lot of people do...like so...
It's all up to the wearer's choice and convenience. 
Why indians been wearing it for so long?
The saree is a garment that has metamorphosed into its current form from an ancient history of very different looking garments. Over the centuries, it has undergone several improvisations to suit changing lifestyles and environments. There are multiple ways in which the saree is draped, and it changes from region to region. Take a look...
India has a very old history...and so it's only natural that women would have used cloth to cover themselves up in varying styles since time immemorial. The saree of today is the result of centuries of improvisations.
Is T-shirt better?
That again depends on the wearer. It's all one's own choice. A saree looks best if one is able to carry it with a certain level of grace. For most people who are unfamiliar with its subtleties,to walk like a queen with 6 yards of cloth wrapped around your body in a seemingly complicated manner would be nothing short of a challenge in itself. That said, a saree is a beautiful garment and I love the way women look in a saree than in any other attire.
Now you decide....T-Shirts or Sarees? :)   

Opinion 2:-

A sari is a 6 to 9 yard piece of fabric, to be draped around the body, as desired. One can get creative in wearing saris, in any manner, depending on the body shape, fabric  and occasion.
It reveals the belly, since the blouses chosen are short. One can choose to show off a good figure and the curves, or conceal the flab with the options given below.
See combinations with T-shirts.
Saris can be worn with a jacket or shirt too.

Opinion 3:-

Good Question. But let me start with another one or more than one actually - 1) why did Victorian era gowns reveal shoulder and pushed bosoms up. 2) why does skirt reveal legs 3) Why do shorts reveal thighs 3) Why does bikni leave nothing to imagination. 4) Why does Scottish skirt show hairy leg of men.

You see something common ? Because they are garments , they are collective evolution of human history.

I can give you many reasons as to why saree is the way it is including that of heat in India but no I am seriously kind of tired of defending a garment which apart from being national dress of this nation, is also something I grew up seeing my mother and her mother and hers wear everyday.

I love it and wear it regularly and no I am not even married. You see no in-laws to force me.

You like Tshirts ? Go ahead and live in them. You see, no outfit is superior to another one or inferior to other.

As an Indian girl, I am not going to explain saree to anyone anymore. I used to but I am now tired of people's obsession with saree bashing.

You don't like navel of millions of Indian women in saree ?  DON'T LOOK.

PS: Seriously, find a hobby.

source :- quora.com