Without splatting it is very cumbersome to try and pass values down through the call stack. But if you combine splatting with the power of the @PSBoundParameters then you can pass the top level parameter collection down through the layers.

Function Outer-Method
{
    Param
    (
        [string]
        $First,
        
        [string]
        $Second
    )
    
    Write-Host ($First) -NoNewline
    
    Inner-Method @PSBoundParameters
}

Function Inner-Method
{
    Param
    (
        [string]
        $Second
    )
    
    Write-Host (" {0}!" -f $Second)
}

$parameters = @{
    First = "Hello"
    Second = "World"
}

Outer-Method @parameters