Exactly mate. Like it or not the only teams that aren't feeder clubs for other teams are Real Madrid and Barcelona. Let's face it united had won everything there is with Ronaldo, but they still couldn't keep hold of him when united came calling.
Spurs have lost walker, but are able to retain their other players, due to champions league football. If they drop out of the top 4 next year, the vultures will be circling for Kane and Ali.
Young hungry, talented, players who are desperate to improve is the way forward for us as you say.