Or is it just me?
We have kung-fu man 
Ninja man 
And Samurai man 
Mostly noted for their mechanics and dank plays.
Ofc you have things like azir, kalista, riven, and vayne. But Ionia man, they get all the low cd flashy play mechanic champs.
Cause Ionia is very Asian in design. You know what else is very Asian? Anime. Anime is very flashy leading to people believing that things in the east are also flashy. So when making eastern characters, they make them as flashy as possible.
Am I doing satire right?
you forgot 
I think it's to fit the theme of Ionia.
Noxus has a moshpit army with deadly weapons, shown in gameplay through typically very harsh, brute force style of play with big numbers. Demacia is a well trained army with regal and well made weapons, shown in gameplay through patient play with high moments, usually requiring some form of set up. Freljord is an icy wasteland full of barbarians and the like, shown in gameplay through tenacious characters that reduce the movement and attack speed of enemies. Shurima is a place of ascended power that is at it's max. Most champions from Shurima are known for something in-game, whether it be infinite scaling, an oppressive early game, insane zoning potential, range, or being the best at countering AD. Bilgewater is a harbor for tricky yet vicious styles of combat. It has a lot of variety due to this, but most usually have a way to have some tricky to set up, yet insane big moments. Bandle City is a place for no brute force warrior. They all rely on their weapons/gadgets to win and usually fall like flies when focused. Piltover is the city of the future, showing off very high-tech mechanics. Their gameplay commonly has unavoidable damage to showcase this and has some unique mechanics. Zaun is the underbelly of Piltover and is filled with toxic fumes and dark dealings. This is shown with most Zaun champions relying on ambushes and/or poison to kill their foes. The Shadow Isles are the Shadow Isles. Most people there are really good at killing people and/or interact with death itself.
Meanwhile, Ionia has none of the above. Their weapons are usually pretty sharp, sure, but the main strengths of most Ionian champions comes through their will, mind, spirit, and body. This is, without a doubt, the hardest form of combat to master and be at equal ground with other fighting styles that use magic, weapons, and technology to fight. Therefore, most Ionian champions are seen as hard to play.
