Stoßlüften is down to a precise science here.

You mean, not everyone in the world is using a multiple-wireless-thermometer and -hygrometer arrangement to determine the exact optimal millisecond to switch from one complex apartment window configuration to the next?

As a German, I am really confused by that idea... ;-)

Well, but still during the eighties most of the houses in my area burned brown coal in crude ovens to heat their homes, the cars spit out blue, only half-burned lead-enriched and carbohydrate-tasting exhaust in huge amounts, while the surrounding forests were dying because of all the unfiltered sulphuric acid the power plants emitted.

During winter, we often had dense smog in the valley, heavily tasting like a mixture of wood smoke and burnt rubber and triggering frequent coughing.

And just staying in the inside also wasn't that great of an option, as constant cigarette smoke was a given everywhere.

If I had to name one thing that definitely has gotten better by an insane amount, it would the air quality.

So why did the cute one-eyed little fella told you something to crush your soul?

(I hate that stuff like this is increasingly destroying the once really good POV meme format)

What always gets me with this kind of tests:
This is remarkably like the kind of errors generative AI typically does when told to generate images of stuff.

Generally agree, but where did the air quality decrease compared to some decades back?

(80s kid here, so maybe my brain is to slow to realize it, because of the remains still in my bloodstreams of the lead fumes and unfiltered coal power plant exhausts I inhaled back then...)

Spot on, I live in Germany!
This kind of shutters are standard here and are actually great!
But during longer heat they still loose most of their advantage, as at some point the heat has just seeped through the massively build outer walls (and stays in the walls for a nice, cozy bedtime temperature of ~30°C on the upper floors...)

1. Tropical nights
2. German houses (massive walls acting like night storage ovens after some days in the heat)

.
Not that I didn't try the fan solution. Done properly, I managed to reduce the air temperature by about 1°C by early morning compared to the evening.

It mainly covers your base consumption.
Profit you make is the savings you have because you have to purchase less electric energy from your provider.
Typically pay for themselves within 3-4years for such an installation on south facing balcony in my region.
The rest of the 20years of its lifetime is just free money after that.
I have a two panel installation, saving me ~120€ per year.

No, this type of external shutters is standard for German homes, so tells not much by itself.
As for the efficiency: Buildings here are mainly designed for colder weather, with the intent to keep the warmth inside and at a constant temperature (thick, massive walls and insulation on the outside). And at this, they are very efficient.
But during the recent, unusually long heat waves, once the heat managed to seep in (typically after 3-4 days), you are basically screwed, as you have no chance to lower the inside temperature without AC.
Temperature stays high even at night, trapped in the walls.

Why?
The external shutters only help keeping the sun out during daytime.
Once the walls have heated up (which takes 3-4 days, as these are massive brick walls), you have a nice constant 30°C, day as night...

The only minor upside from the fact, that it also is one of the driest summers in my region so far:
No mosquitos.
Even the freshly imported Asian Tiger Mosquitos, which normally start roaming in July and need less open water, are almost completely absent (and they are only active during daytime).

Well, much better than the constant 32°C the neighbour in the topmost apartment had at the end of the big 10 day heatwave!
Especially when you manage to keep the humidity in a lower range.