Is it possible to remove the extra arrow function here?

Hi!
The tutorial has an example like this:

class Square extends React.Component {
  render() {
    return (
      <button
        className="square"
        onClick={() => this.props.onClick()}
      >
        {this.props.value}
      </button>
    );
  }
}

This component used in the Board component like this:

renderSquare(i) {
    return (
      <Square
        value={this.state.squares[i]}
        onClick={() => this.handleClick(i)}
      />
    );
  }

We have closed the context in a function that we pass to onClick in the Board component.
But why don't we just pass this.props.onClick to onClick in the Square component? Why are we using closures here if we already have the right context inside?

I wrote like this: (link to codepen)

class Square extends React.Component {
  render() {
    return (
      <button
        className="square"
        onClick={this.props.onClick}
      >
        {this.props.value}
      </button>
    );
  }
}

This works successfully

It is clear that the variant from the tutorial will also work. But further it says:

When we modified the Square to be a function component, we also changed onClick={() => this.props.onClick()} to a shorter onClick={props.onClick} (note the lack of parentheses on both sides).

So my variation only works in a functional component? But above it also worked in class components. I think this might confuse some people.

Empieza leyendo las secciones enlazadas del tutorial sobre elevar el estado y los componentes de función, y después compara los dos ejemplos de onClick y la explicación que los acompaña. Comprueba si el ejemplo del componente de clase necesita aclarar la diferencia entre pasar un callback e invocarlo. Se considerará terminado cuando el tutorial explique claramente por qué funcionan ambas formas y cuándo es apropiada la forma más corta.