My suggestion is that bras should be chosen for the occasion just like our outfit. The type of the activity, the body structure should decide what kind of bra a woman is wearing.
Many lingerie experts emphasis on the importance of underwire bras, though on the other hand nowadays there is a huge fashion of bralettes also, and time-to-time we can hear doctors saying that wearing an underwire bra can cause even cancer. There are many pros and contras of wearing both type of bras if you are not wearing them for the right occasion, or in the right size. Right size and a consciously selected bra is crucial in the case of underwire bras. Women’s breasts can be described with two qualities when it comes to size and shape: the projection of the breast and the dimension. When a woman selects a bra size, she is actually selecting as per the projection, but the dimension is pre-decided by the manufacturer. It means that the underwire that the manufacturer stitches inside the garment is pre-decided, and you can hardly do anything about it. Brands tend to state that they have the best shape, and they try to use a bit different shape of underwires. So it is possible that the same size and the same style of bra will fit you differently in case of different brands. On the other hand you won’t find such issues with a non-wired bra, but that might not give you the required support in certain activities.
What I want to say is that underwire and non-wire bras can be equally good if we select them consciously. Both have their own validity and occasion.