The article doesn’t really mention it and only focuses on it providing an incorrect value (150% when it’s already at 150%), but this bit that’s added as a reader context to the Tweet is even bigger blunder:

The user asked how to increase text size, but Copilot incorrectly advised changing the “Scale” option in Settings > System > Display. This enlarges text, but also resizes UI, apps, and other elements

To change only text size, go to Settings > Accessibility > Text size.