In an earlier time not too far back, parents were advised that their infants should never be "shod" until they had learned, barefoot, to stand and walk on their own. When shoes became necessary for small children, a "proper arch support" was considered mandatory.

"Flat feet" were considered an impediment, and in fact were one of the diagnostic criteria for a lower fitness classification in the military services draft system through most of WWII. Sufficiently flat feet could, and did, cause some draftees to be rejected for military service.(And was sometimes a handy explanation for those rejected for a less "socially acceptable" reason, hence the difficulty in estimating how common such rejections were.)

Shoes were made with "arch supports" that typically elevated the inner arch area by at least 3/8 inch, and often a bit more, with the support extending up to a third of the way across the foot.

Sometime at about the time that the famous "Dr Spock" became the ultimate guide to child rearing, the advice changed to never allowing an infant to stand without proper shoes, with "proper" consisting of a dead flat sole to "prevent flexure of the foot to improper shape." I don't know that Spock made this recommendation - it was just in about that time period.

The result is that persons born after the mid-late 1950s or so typically leave a wet footprint on concrete more resembling the track of a duck than what was previously pictured as a "human footprint." Arch support built into shoes virtually disappeared, and over a period of a couple of decades the "arch support inserts" commonly available degenerated into little more than "sole liners."

The main point here is that how your were treated as a child may have a profound effect on the shape of your foot, and on your requirements for footwear. Since we old-farts are not a significant "market force¹," even the good support inserts some of us would like to have are unavailable in ordinary retail markets, and so far as I've been able to determine are not even available by special order from the likes of Dr Scholls.

¹ Consider the greater profit in selling "fashion designer" footwear to growing kids who will outgrow them in a few weeks and will need something new and more fashionable (being then more "mature") vs someone like myself who even at 25 usually wore one pair of shoes (boots) for 3 to 5 years before the next purchase.

As has been mentioned by a couple of people, an arch support that rolls the support to the outer edge of the foot can be helpful for some people. A "metatarsal pad" just behind the basal joint of the toes may help to stretch the tendon(s) in the sole of the foot and may help some. At one time, you could buy Dr Scholls inserts combining both features with useful dimensions; but I gave up even looking for them several (15-20?) years ago. Good luck if you need something of this sort.

A "specialist" may be the only place you'll find anything useful, particularly if your needs aren't the same as for the "barely crippled" with nearly the currently popular shape in feet. (e.g. the frequent Birkies recommendation - enough for some but not for all.) But it is critical that you find a solution that works for you.

John