There is a tendency to snowball our situation into absolute despair. In the last two days I have seen - we absolutely cannot sign any top players, and finishing 1 point off 4th and in the Europa final means that we have no chance of competing this season. We really seem to be taking a glass half empty approach.
On the transfers, I would treat Ndombele and De Ligt differently. De Ligt is the hottest transfer in town, seen as a once in a generation defender. A number of top teams (PSG, Barca, Juventus, Liverpool, United) have made him first choice and the choice is in his hands. We stand no chance when there are so many clubs that can all offer more money and Champions League (the facts bear this out).
Ndombele, on the other hand, was billed as a top prospect but did not have the same competitive market. Barcelona went for a once in a generation midfielder from Ajax; Juventus went for 2 free CMs to position themselves for De Ligt. And Madrid drew up a priority list of midfielders that placed him at best 3rd. The Madrid situation has tied up United as well. Liverpool's midfield is stocked and City specifically needed a Fernandinho replacement, with Ndombele not having the refined passing yet for their system. This opened up a path for Spurs to chase him alone all May/June.
I agree with Klaus that we could have gone after Ndombele if we had the ambition. De Ligt, however, was out of the question.