There's T-shirts and then there's T-shirts.
Years ago, I ditched mine and bought some that were expensive (for a T-shirt); the material was good quality - slightly thicker than the normal T, and with different neck styles. The 'envelope' neck was particularly flattering. Some of them had turn up cuffs on the sleeves and 'tabard' style.
... but they were still T-shirts.
The trick is, I think, to buy them large enough, and not to buy the really cheap, thin ones that lose their shape and become baggy-looking. The ones I bought would flatter anyone's figure I think.
The problem is, I removed all the labels and can't remember who makes them (if they are still manufactured) and the shop that sold them has now gone out of business.
It was 30 years ago, and I'm still wearing them.