I'll bite.

How does this promote simple living?

It only does so if you believe that reducing spending is the primary goal of simple living. For some it is but for many it's more than being extremely frugal.

I'd argue that in a lot of cases buying coffee out is actually quite simple compared to making it at home. I rarely use it but we have a Starbucks on the ground floor of my work building. So, it is objectively simpler for me to walk up and have a cup of coffee within 10 seconds than it is to brew it at home. At the same time, this sub isn't /r/convenience either.

That's mostly an argument about the semantics of what "simple living" means. That isn't my problem with the graphic. My main problem is that the graphic fixates on the absolute easiest targets (DAE Starbucks coffee is a ripoff?!?).

If the argument is financial, I can think of ways to achieve a better savings than cutting Starbucks. There also easy enough that an average person can accomplish them in about 2 hours.

If the argument is any consumption is more complicated than no consumption, food is probably the worst area to target because you have to eat something.

The whole graphic is what I would define as being "penny wise and pound foolish" from both financial and simplicity perspectives. However, it's an easy topic to circlejerk about for a huge karma grab.