The comments in that article bring up that there's a user setting to scale only the text. For the history, read: https://mindtheshift.wordpress.com/2015/04/02/r-i-p-rem-viva-css-reference-pixel/

Respecting a legacy setting just because it exists is dogmatic though. The accessibility scenario is simple. People with low vision need:

• Things to be bigger (at a minimum, text)
• No horizontal scrolling (it's very hard to read quickly while panning back and forth)

Normal browser zoom + responsive design meet those requirements without issue. There's no need to support the large text settings as well.