Special Note: Please note that this scenario is meant to be read as entertainment, not as an accurate prediction of the future. Also note that the viewpoints and opinions that may come across in this scenario are not necessarily the viewpoints and opinions of the author.
Around the 2020s, the camisole will replace the bra as the undergarment used to support women's breasts, just like the bra replaced the corset in the 1920s. A camisole is a sleeveless undergarment for women, normally extending to the waist. The camisole is usually made of satin, nylon, or cotton.
In modern usage a camisole or cami is a loose-fitting sleeveless woman's undergarment which covers the top part of the body but is shorter than a chemise. A camisole normally extends to the waist but is sometimes cropped to expose the midriff, or extended to cover the entire pelvic region. Since 1989, some camisoles have come with a built-in underwire bra or other support which eliminates the need for a bra among those who prefer one. Recently, camisoles have been known to be used as outerwear.
These camisoles of the future will combine the support of the antiquated bra with the comfort of a men's T-shirt. Eventually by the late 2020s, the camisole will be made for women in sizes 14 and above. However, a niche market will still exist for the bra in the live theatre and in motion pictures for films that take place anywhere from the mid 20th century to the early 21st century. Also, certain vintage clothes just won't look right with a camisole so even in the 2050s, bras can be purchased for a premium at Internet sites that sells vintage and 20th century period garments. 3D printers, on the other hand, will allow women to manufacture their own camisoles out of melted nylon. High waisted "granny panties" will make a comeback by the year 2050 and the momentum will carry on until the year 2155 when women will want to wear "sexy panties" again.
However, most retail and department stores will stop selling bras altogether after the summer of 2045. Instead of matching bra and panty set for young teenaged girls, there will be matching camisole and panty set. Of course, the daughters of North America will be the first to leave their mothers' stuffy world of bras behind and launch a rebellion into a world where camisoles are queen of the undergarment world. While Europe and Asia will probably be about 1-5 years late joining the camisole revolution, camisoles will quickly develop interest in England and France. Meanwhile, the rest of Europe will take their precious time waiting for the fashion designers of Milan to run out of ideas to spruce up the bra with new innovations and designs before jumping in on the idea of camisole replacing bras.
This conservatism in European fashion is why women wore corsets in the 1930s while their North American cousins were already wearing bras. Australia will be 5-10 years behind North America and most countries in the Middle East will force their women to keep wearing bras until the 2060s (partly due to religious reasons, even though a camisole covers more of the body than a bra, and partly due to chauvinist clerics finding the camisole to be a wicked tool of Western feminist civilization). Despite all this religious, political, and secular hype about the camisole replacing the bra, this new fashion trend will become popular with the females who were born in the year 1997 or later.
Women of this generation will see bras as a antiquated garment and movies aimed at them will see bras worn only by "elderly women", and people in nursing homes, because 90-year-olds don't really follow the fashion. Instead of having to lace up the back, the camisoles of the future can simply be slipped on like a T-shirt.