There are two failure modes in IT strategy. Most CIOs only track one.
Execution drift is visible. Projects slip. Budgets overrun. Milestones move. Status reports are built to catch this.
Strategy drift is invisible. The plan stays static while the world underneath it moves. Teams hit milestones. Dashboards stay green. The document remains intact. And the enterprise quietly invests a year of capital into a direction that stopped being correct in month three.
Strategy drift is more dangerous than execution drift, because it's silent.
You cannot catch it with a static document. The document is the thing drifting.
If your primary strategic artifact is a PowerPoint refreshed annually, you have no mechanism to detect strategy drift. You only find out when it's already expensive.
How are you measuring it?