function Get-UsersPath {
<#
.SYNOPSIS
    Get the path to the root of the Users folder for Windows or macOS.
    Will optionally append the provided username path as well, when provided.

.PARAMETER Username
    [Optional] The username folder to append. This is provided as a helper parameter.
#>
    [CmdletBinding()]
    Param(
        [Parameter(Mandatory = $false, Position = 0)]
        [string]$Username = ""
    )

    $systemDrive = $env:SystemDrive
    if ([string]::IsNullOrWhiteSpace($systemDrive)) {
        $systemDrive = (Get-Item -Path $PSScriptRoot).PSDrive.Root
    }

    # (Join-Path C:\ "") -> C:\
    # (Join-Path C:\ $null) -> C:\
    return (Join-Path (Join-Path $systemDrive "Users") $Username);
}