But unfortunately it is the type of thing that, although obviously a superior solution, is unlikely to be adopted in the rest of the world. Where I live, as, I think, in most places, people would think you were very strange if you put those kinds of metal shutters on your windows, and I can even imagine neighbours being displeased with you as it makes it look like it is a bad neighbourhood.

I'd prefer to just have less outdoor light since blocking out all outdoor light also blocks out sunlight which can mess up your circadian rhythms.

I'm unfamiliar with this, but I'd love some well-done black out shades - got a link or a brand?

Very common in Italy as well - search Images or Youtube for "finestra tapparelle" for an idea. The sound of tapparelle is super ingrained in many european minds, i.e. https://italybeyondtheobvious.com/taparelle/

They are also good for deflecting debris :)

In Germany they are called rolladens.

The best thing ever!