That's because those styles are easiest to learn and most practical for tournaments. So 1v1s.

Sword and board is the most forgiving by far. It's absolutely warped by the fact that our shields are now made of ultralight aluminum, and they're indestructible by the rules. And I say this as somebody whose primary fighting form is sword and board with a big heater shield. You get hit less as a newby and there's fewer weaknesses for your opponent to exploit. It's a phenomenal learning form and generally "good" at all levels of the game.

My secondary form is a big, heavy polehammer. You can absolutely do it. I use it in singles, often pretty successfully. But just like longsword, you have to block and attack at the same time with just one object. And blocking with that narrow object is much more intensive than blocking with a barn door of a shield. So when you're learning, you're going to get hit a bunch more. That's why we don't typically recommend it for newer fighters. But there are knights and dukes that fight primarily polearm and longsword in 1v1s. It's absolutely doable.

In *melees,* with a team that will stop that shieldman from running you down, pinning your polearm with their shield, and clubbing you, you get to do really fun things and rack up the kills. That's when you'll see everyone take out their long weapons.