What's the point of using event callback in Blazor?

I was wondering if we call a function directly, why should we use event callback?For example, I use an event callback to set the colour of a component from the child to the parent.

This is the child component:

<button @onclick="OnButtonClick">Click me</button>@code {    [Parameter]    public EventCallback<string> OnColorChange { get; set; }    private async Task OnButtonClick()    {        await OnColorChange.InvokeAsync("new-color");    }}

This is parent component:

<ChildComponent OnColorChange="HandleColorChange" />  @code {    private string currentColorClass = "default-color";        private void HandleColorChange(string newColorClass)    {        currentColorClass = newColorClass;    }}

So, instead of the definition for HandleColorChange as a public static method, just call it directly, like this:

ParentComponent.HandleColorChange("new-color");

This isn't the only problem, we use JS interop to call C# functions, although we can handle all of these by calling them directly.The final question is, when should a method be called directly and when shouldn't it?