I feel like I’m going crazy at moments like this.

Wikipedia on Metric Time:

The modern SI system defines the second as the base unit of time, and forms multiples and submultiples with metric prefixes such as kiloseconds and milliseconds.

Edit: Attention that this is the SI second, not a decimal second

Wikipedia on Decimal Time:

This term is often used specifically to refer to the French Republican calendar time system used in France from 1794 to 1800, during the French Revolution, which divided the day into 10 decimal hours, each decimal hour into 100 decimal minutes and each decimal minute into 100 decimal seconds

metric-time.com :

With metric time the day is broken into 10 hours.
A metric hour is broken into 100 minutes.
A metric minute is broken into 100 seconds.

So either Wikipedia is wrong or the website.

Then the wikipedia is wrong? Because what the website you linked calls metric time Wikipedia calls decimal