The Leafs accumulated talent, but failed at step 2, which is to build a team. That requires defensemen, grinders, etc. They have a few great forwards, that's it. You build a plan to shut those down and the Leafs really can't beat most playoff teams over a 7 game series.
They shouldve acquired defensemen as prospects because getting them now in their prime costs a premium. You almost always have to downgrade in talent when dealing an F for an RD, often for an LD too. They also have cap problems, so that doesn't make it easier.
Have they failed? They have made the POs three straight years with a young team. Why is that a fail?
If they focus on the blue-line instead, maybe their young offensive forwards don't do as great because teams can really only focus on them.
Sure every single move made by a NHL team can be questioned, but there is one thing that is pretty absurd and that is that the starting point of all these claims are "what Dubas failed at was" or other ways of saying that.
If Kakko is a hit, have we failed unless we have won a Cup in 2022?