I never bother with WASD or arrows, mouse is most comfortable for me. Not sure about why keys have an advantage over mouse, but ok, tastes and habits are different.
It's much faster. In most RPG Maker games I can use one hand to control the entire game.
- Movement with arrow keys
- Confirm with enter
- Cancel with numpad 0
These are default keybinds. A lot of games also have shift and/or control bound to actions like running, skipping, or hiding text boxes.
The mouse control in RPG maker games is often sucky because the path finding isn't great, so you can't just click once where your character needs to go. Because of how the camera works in RPGM (fixed on character, but bounded by map), you get jarring transitions between the camera following and clipping, and throws the mouse position off. In your game, you're not doing gridded movement, but rather free 2D movement. This means that the pathfinding has an even harder time, and gets caught on corners and door frames. Simply using keyboard is just much less finicky (when the keybinds work).