Key takeaway
A plan that is slower to update than the project is to change will always be out of date.
Most project templates die the same way. Someone fills in the scope, the milestones, the owners, sends it around for sign-off, and then the first change request arrives before the kickoff call has even finished. The document is now wrong, and nobody goes back to fix it, because fixing a document is friction and the project has already moved on.
The problem is not the template's content. It is the fact that a document is a snapshot, and a project is not a snapshot, it is a moving target from day one.
A living record instead of a document
The fix is not a better template, it is not treating the plan as a document at all. Scope, milestones and risk need to be things you can update in five seconds when they change, not things you have to reopen, reformat, and re-circulate. If updating the plan is slower than the project changing, the plan will always be behind, no matter how good the original template was.
That is a design problem, not a discipline problem. Teams that fall behind on their plans are usually not undisciplined, they are using a tool that makes staying current expensive.
What to look for instead
A workable project record should let you change an owner, a date, or a status in one click, should show you immediately what that change affects downstream, and should not require anyone to "update the deck" before the next meeting. If your plan needs its own maintenance project, it has already lost the argument against the spreadsheet it was supposed to replace.