When deleting the top folder in SOLIDWORKS features tree all sub features are not get deleted so it is required to select all of them one-by-one in order to delete folder content. This is not always possible to do in one step due to the features relations:

Manually deleting the folder feature
Manually deleting the folder feature

The macro below allows to delete all of the features in the selected folder in one click

Deleting the folder with all children features
Deleting the folder with all children features

Macro can optionally display the confirmation dialog with the list of features about to be deleted

Const SHOW_CONFIRMATION_DIALOG As Boolean = True

Dim swApp As SldWorks.SldWorks
Dim swModel As SldWorks.ModelDoc2

Sub main()

    Set swApp = Application.SldWorks
    
    Set swModel = swApp.ActiveDoc
    
    If Not swModel Is Nothing Then
        
        Dim swSelMgr As SldWorks.SelectionMgr
        Set swSelMgr = swModel.SelectionManager
        
        Dim swFolderFeat As SldWorks.Feature
        
        Set swFolderFeat = swSelMgr.GetSelectedObject6(1, -1)
        
        If Not swFolderFeat Is Nothing Then
            
            If swFolderFeat.GetTypeName2() = "FtrFolder" Then
                
                Dim vFeats As Variant
                vFeats = GetFeaturesInFolder(swFolderFeat)
                Dim i As Integer
                
                If Not IsEmpty(vFeats) Then
                    For i = 0 To UBound(vFeats)
                        Dim swFeat As SldWorks.Feature
                        Set swFeat = vFeats(i)
                        swFeat.Select2 True, -1
                    Next
                End If
                
                If SHOW_CONFIRMATION_DIALOG Then
                    
                    Dim featNames As String
                    
                    For i = 1 To swSelMgr.GetSelectedObjectCount2(-1)
                        
                        On Error Resume Next
                        
                        Set swFeat = swSelMgr.GetSelectedObject6(i, -1)
                        If Not swFeat Is Nothing Then
                            featNames = featNames & vbCrLf & swFeat.Name
                        End If
                        
                    Next
                
                    If swApp.SendMsgToUser2( _
                        "Delete the following feature(s) and all absorbed features?" & vbCrLf & featNames, _
                        swMessageBoxIcon_e.swMbQuestion, _
                        swMessageBoxBtn_e.swMbYesNo) = swMessageBoxResult_e.swMbHitNo Then
                        End
                    End If
                End If
                
                swModel.Extension.DeleteSelection2 swDeleteSelectionOptions_e.swDelete_Absorbed
                
            Else
                MsgBox "Selected feature is not a folder"
            End If
            
        Else
            MsgBox "Please select folder feature"
        End If
        
    Else
        MsgBox "Please open model"
    End If
    
End Sub

Function GetFeaturesInFolder(folderFeat As SldWorks.Feature) As Variant
    
    Dim swFeatsColl As Collection
    Set swFeatsColl = New Collection
        
    Dim swNextFeat As SldWorks.Feature
    
    Set swNextFeat = folderFeat.GetNextFeature
    
    While Not swNextFeat Is Nothing
        
        If swNextFeat.GetTypeName2() = "FtrFolder" And swNextFeat.Name = folderFeat.Name & "___EndTag___" Then
            
            Dim swFeatsArr() As SldWorks.Feature
            
            If swFeatsColl.Count > 0 Then
                
                ReDim swFeatsArr(swFeatsColl.Count - 1)
                
                Dim i As Integer
                For i = 0 To UBound(swFeatsArr)
                    Set swFeatsArr(i) = swFeatsColl.item(i + 1)
                Next
            End If
            
            GetFeaturesInFolder = swFeatsArr
            
            Exit Function
            
        End If
    
        If Not Contains(swFeatsColl, swNextFeat) Then
            swFeatsColl.Add swNextFeat
        End If
    
        CollectAllSubFeatures swNextFeat, swFeatsColl
        
        Set swNextFeat = swNextFeat.GetNextFeature
        
    Wend
    
End Function


Sub CollectAllSubFeatures(swFeat As SldWorks.Feature, coll As Collection)
    
    Dim swSubFeat As SldWorks.Feature
    Set swSubFeat = swFeat.GetFirstSubFeature
        
    While Not swSubFeat Is Nothing
        
        If Not Contains(coll, swSubFeat) Then
            coll.Add swNextFeat
        End If
        
        CollectAllSubFeatures swSubFeat, coll
        Set swSubFeat = swSubFeat.GetNextSubFeature
        
    Wend
    
End Sub

Function Contains(coll As Collection, item As Object) As Boolean
    
    Dim i As Integer
    
    For i = 1 To coll.Count
        If coll.item(i) Is item Then
            Contains = True
            Exit Function
        End If
    Next
    
    Contains = False
    
End Function