Why dictionary very slow ,is dictionary have maksimum data

I am using excel 2016 64 bitt
I have data in col a:j
My key is a&b&c...&j
But it very slow,is so multi Compleks criteria
My data 80.000 row

sub test()
Dim txt$,i&,x
With [A1].CurrentRegion
  x = .Value
  With createObject("Scripting.dictionary")
   For i = 1 to Ubound(x)
    With application
     txt = Join(.transpose(.transpose(.index(x,i)),",")
   .item(txt) = .index(x,i)
   End with
 Next i
End with
End with
End sub

But if using array is very fast
But my data not similar arrange data
Must to sort but so complek data imposibble to sort

sub arr()
Dim ar(),i&,n&, x,j&,k&
x =[a1].CurrentRegion.value
  Redim ar(1 to ubound(x),1 to ubound(x,2))
  For i = 2 to ubound(x)
     n = i-1
     For j = 1 to ubound(x,2)
        If x(i,j) = x(n,j) then
          k = k + 1
          ar(1,j) = x(n,j)
          ar(k,j) = x(i,j)
        End if
     Next j
  Next i
End sub