De Gea is a better alternative for Newcastle United. He is younger than Hugo Lloris and I think he is a better goalkeeper. But today Newcastle United urgently need a goalkeeper. So Hugo Lloris can also solve Newcastle United's problems. De Gea is not a mandatory alternative. But we have to say that what happened today was a planning error. Newcastle United's management should have foreseen this situation in advance and signed a well-qualified backup goalkeeper. I think we can see that they failed in this regard.
De Gea is only 3 years younger than Lloris, it's pointless for them to sign an old goalkeeper. There's no good goalkeeper out there, the current Tottenham goalkeeper which is Vicario is fine enough. They currently have 3 amateur goalkeepers, so they still have many substitute goalkeepers.
Tottenham need to find new defender since there are five injured defenders right now.
For the age of goalkeepers, David de Gea's current age can still be used for a few more years, but with a note that he will be able to give his best in his game. Indeed, young players will give a very long time, especially in the position of goalkeeper will usually be difficult to replace.
Seeing from the last performance when he was still in the Manachester United uniform, actually his game was not disappointing, it's just that he didn't get the trust of the coach which eventually made him have to leave. In fact, his replacement players who have 6 years of age below him are also unreliable now.
I will actually say that if they have to get a goalkeeper De Gea is going to be a great option for them. But they should not expect anything long term from him. Probably 2 years of good service is expected from him at the maximum. But on the other hand, I also agree that they should get a defender first. Defense is a very big problem for them at this moment. And with also injuries being a big problem, defense is and should be the main priority for them right now to fix. The amount of goals that they are conceding is definitely not the fault of the goalkeeper in my opinion.