The issue is that this kind of authoritarian military organization needs a clear leader, and without that, cannot function properly. That leader used to be the US. Even under Trump 1 (and even though i disagree with the decision), forcing NATO member to think about the 3% rule was ultimately something someone have to do (my preference would have been to lower the threshold), and that someone was the US. I also think it would need a pre-2008 France, who refused to be under the integrated command, to build a sort of trust and respect between members.
Ultimately though, the Irak invasion shattered the trust and status quo, and i agree 100% with people saying NATO must die. Alliance that are more than a reactive defensive pact and force member into attacking unrelated countries should disappear. Just get nukes, and pray you won't have to use them.