Unless we start winning stuff yep.
Aguero, Hazard, De Bruyne, Yaya, Kompany etc prove you can keep world stars happy in this country if you fucking win things.
Madrid, Barca etc know us and Spurs will sell eventually because our players win fuck all here so will want to leave.
Champions league would help, but lets face it we need to start regularly winning leagues to keep these players happy.
You go to Spain you have a 50/50 chance of winning the League title every year.
Same in Germany. Probably almost the same in Italy and France.
This is certainly the hardest league nowadays to have a dynasty in, as proven by the fact no one ever defends the fucking title.
So whats to keep these guys here? Nothing unless you prove that you can win it.