For the vast majority of human (homo sapien) existence (approx 350,000-40,000 years ago), our feet were non-shoed. While vulnerable to sharp objects, cold weather, piles of poop, and bites from creatures (any of which--especially when combined--could have been a death sentence), this kept our arches strong and our toes spread wide.
It is estimated that sometime around 40,000 years ago, we started wrapping leather around our feet, providing some protection from cuts, weather, bites, and poo-related infections.
The oldest known shoe was made from tree bark around 10,000 years ago.
Around 8,000 years ago, flip-flop type sandals started showing up in warmer climates, though bare feet were likely preferred most of the time.
The oldest known leather shoe is about 5,500 years old (pictured below), which as you can see still allowed for free movement of the toes and still demanded the muscles in one's feet to provide an arch. These were most common in cold climates.
Over the next few thousand years, as civilizations advanced and grew, so too did our design and use of footwear.
Around the 15th century in Europe, pattens became popular (unless you were poor or a slave, in which case, you were barefoot) as a means of keeping one's feet (and shoes) out of puddles, mud, and human excrement (city-dwelling humans were disgusting animals during this period). Around this time, shoes with a heel became popular among (wealthy) women and men.
By the 17th century, leather shoes with a sewn-on sole were common. But it wasn't until around 1800 that shoes started differentiating between the left and right foot.
By the end of the 19th century, shoe production was largely mechanized. While mass-production got shoes on more feet, the process offered very little variety and individualization ("This shoe comes in a size men's or a size women's."...”Uhh, I guess I'll take the size men's"..."Very good, sir. Good luck, sir.").
The modern shoe--sewn-on sole, raised heel--was made out of leather until the mid-twentieth century, at which point, advances in rubber, plastics, and synthetic cloth opened the door to what we wear today.
For the most part, very little change took place until the 1970's when running started becoming popular. It was around this time that shoes started adding arch support and soft, rounded soles for cushioning. This design trend continued for the following few decades.
At the turn of the last century, however, barefoot running or minimalist running has become popular, which has caused a shift in the design of running and training shoes. Now, running/training shoes are lighter, have minimal arch support, and use a limited height heel. This is great news because this style of shoe provides protection while still allowing for the foot to properly articulate and the toes to move freely.
So that is a (very) short history of shoes. Neat, right?
The reason for providing this brief history is to provide some perspective on the length of time shoes have been in our lives, and how they have become a likely culprit for the most common foot issues many of us are dealing with today. Like many things that were invented to solve of a problem of the era, their purpose has changed over time (safety -> fashion), and have stuck around without much consideration to their original purpose. But that is changing and it's why nerds like me are talking about the importance of developing strong feet.
Shoes are only part of the problem, of course. Spending so much of our time sitting these days, having weak feet from prolonged shoe use only exacerbates these movement issues. But this is a big topic with several active controversies. I also don't want to give the impression that shoes don't serve a purpose. In fact, shoes are better at serving a specific purpose than ever before. You can, and probably should, have several pairs of shoes each designed for a different purpose-a pair of shoes for training, a pair for walking/jogging, and a pair for casual outings, for example.
The importance of having strong feet, particularly when training, can not be understated. Every movement that involves your legs begins with your feet. If your feet are weak and your ankles are unstable, the entire movement becomes compromised. If you have noticed that your toes are being pushed together, take steps now before it gets worse. Get those toes spread apart and walk around barefoot when you can. There are also shoe companies now that make shoes with a wider toe box that don’t smash your toes together. I've tried a bunch and my favorite pair is from Inov-8.