Coming from the military world, the chelsea boots appeared in the streets in the middle of the 19th century. Queen Victoria even used to wear them for horseback riding. We recognize them by their elastic band that allows us to put them on easily.
With a boom in the 1960s - thanks to the Beatles - they have remained a timeless item, both in the men's and women's wardrobe.
In my opinion, chelsea boots are among the only boots that can be worn with a suit.
The pants seem to fall nicely on the shoes, the colors of wool and leather contrast nicely: you stay on something elegant. Be careful however, some purists consider this association as a heresy (one should not wear boots with a suit)... But beyond any dogma, the result remains interesting.
This ease to be worn with a suit makes it an ally of choice for chic casual outfits. As here, opt for a long coat (it also works with a trench coat in spring), well-cut jeans or a chino, and a nice shirt.
More and more, we find chelsea boots in streetwear looks. Jeans, a sweater and a bomber will do the trick: boots will contrast, bringing research to the look. It would still work with sneakers, of course, but the effect would be completely different.
The only downside is that people with wide feet will find it harder to find what they're looking for, because it's basically a narrow shoe.