Remember bra burning in the '60s? Wearing bras and girdles were simply uncomfortable. Squeezing into shape making devices was just the thing, though. These clothes were designed to give women a shape. Bras were too often fashioned into creating bosoms that resembled bombs: pointy and sticking out. They were also not helpful if you had to run; menstrual hormones often swelled the bosom and running made bouncing just painful. Running was just painful.
People were not into gyms, or exercising, so artificially creating a pleasing shape was the easy way out. Whatever your shape was, it was in need of some help to suit accepted ideas of what a woman was supposed to look like.
Luckily, now, working out is an accepted, almost, mandatory activity. And sports bras! You can run without bouncing and without pain. Under clothes, breasts have a rounded look. Sports bras are comfortable, too. No stays, or underwires. No hooks. No strap adjustments. The look is more natural. And those horrible girdles! Like sports bras, there are now these slip on stretchy underwear that are also comfortable, and help keep those bulges under wraps. All in all, women can achieve a good form without the torture.