Every time I look at that chart, my eyes glaze over and I decide not to automate. The title text when alludes to this.

I just ... don't get it. I fear I may be a bear of small brain.

As someone else mentioned, there are other valuable considerations the chart ignores, such as likelihood and impact of mistakes.

OTOH automating is an acquired skill, so I learned to say "screw it". Unless you feel you're trying to spend a month to save 10 minutes total, go ahead and automate it - that's how you get better at automating more stuff faster.

Automation also gets rid of context-switching, which has a cost of its own. It may only take you half an hour to do -foo-, but to switch into the mental space for it and switch out again are costs that most people don't factor in.