Wikipedia says the iPhone 5S was released in September 2013, So that's about 6-7 years of updates.
The chart you linked seems wrong to me. Am I missing something?
You're right, the chart is showing OS releases not precise iPhone releases.
It still closer to 7-8 years for the 5S of OS/security updates (just because a new OS version came out doesn't mean security updates stopped completed).
It still closer to 7-8 years for the 5S of OS/security updates (just because a new OS version came out doesn't mean security updates stopped completed).