SharePoint list query alternative or optimization

first of all you are a crack, My query is the following, I am applying your code and I have a very large sp list.... and it returns me 150000 elements but they are duplicates please could you help me

let
sitename ="<your site>", // if a subsite use "Site/SubSite"
listname = "BigList",
baseurl = "https://<your SharePoint URL>/sites/" & sitename & "/_api/web/lists/GetByTitle('" & listname & "')/",
itemcount = Json.Document(Web.Contents(baseurl&"ItemCount", [Headers=[Accept="application/json"]]))[value],
skiplist = List.Numbers(0, Number.RoundUp(itemcount/5000), 5000),
#"Converted to Table" = Table.FromList(skiplist, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
#"Renamed Columns" = Table.RenameColumns(#"Converted to Table",{{"Column1", "Skip"}}),
#"Changed Type" = Table.TransformColumnTypes(#"Renamed Columns",{{"Skip", type text}}),
fieldselect = "&$top=5000", // all fields with no expansion
//fieldselect = "&$top=5000&$select = Id,Title,Person,Date", // list desired fields (no expansion)
//fieldselect = "&$top=5000&$select=Id,Title,Choice,LookupColumn/Title,LookupColumn/Project,LookupColumn/ProjectStatus,Date,Person/LastName,Person/FirstName,Person/EMail&$expand=LookupColumn,Person",
Custom1 = Table.AddColumn(#"Changed Type", "Items", each Json.Document(Web.Contents(baseurl& "/items?$skipToken=Paged=TRUE%26p_ID=" & [Skip] & fieldselect, [Headers=[Accept="application/json"]]))),
#"Expanded Items" = Table.ExpandRecordColumn(Custom1, "Items", {"value"}, {"value"}),
#"Expanded value" = Table.ExpandListColumn(#"Expanded Items", "value")
in
#"Expanded value"