alt Hacker NewsMorse code has some interesting properties that make it an ideal way to communicate when all else fails:
1. It can be transmitted by simple means through many mediums - radio waves (amateur radio, as in the article), light (turning a light on and off), sound (I once used a boat horn to communicate with another boat)... technically I could even tap it on someone's shoulder.
2. It's self-clocking; you don't need a way to synchronize between two operators. One of the amateur radio clubs within range of me, K1USN (https://www.k1usn.com/sst) runs a contest that's limited to 20wpm so that new operators can get used to interpreting Morse on the fly.
3. It's fairly easy to recover after a fault - much easier than, say, ASCII. I might lose a few characters, but much like a smudge on a written page, I can figure out where intelligible letters start again without much difficulty.
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HAM was a nice rabbit hole to fall into, but unfortunately I couldn't muster enough interest to actually get good enough to go "on air".
Some other things that surprised me and may be interesting for other people:
Learning Morse code is like learning a new language. The unit of understanding is not dots and dashes but rather every letter is a unit that one (in modern training) learns to recognize intuitively as such before doing anything else.
On top of that, telegraphy has these three letter Q-Codes where one would assume that these abbreviations are for line efficiency, but also it's because three letters is a nice length that still decodes intuitively as a "word". (Also Q was probably chosen because it so seldomly comes up in "normal" words, so it's like a little attention signal? But that is my speculation.)
One can see in conversation that these three-letter codes often only have to be transmitted once, whereas free text (e.g. proper names) are often sent with redundancy so it's easier to transcribe them as you have to fall back to decoding individual letters. (My ears still sometimes perk up suddenly when hearing Morse code from movies because suddenly I pick up something like CQ without even paying attention.)
People therefore use terms like "musicality" (at least in my language, not sure if that translates to English) to refer to the quality of one's transmission. There is a certain art to it.
One funny exception to the three letter codes that gets used in Germany. If somebody signs off for a lunch break, they'll key ESSEN (translates to "eating"/"food") which would be considered "too long" to decode intuitively but it has a nice drumroll to it so it still works :)
Adding onto your point #1, you can tap it through rock - which has helped people who are trapped in caves communicate & get rescued!
I've told my family that if I'm ever in a hospital bed due and seemingly unresponsive due to injury or illness, to check whether I'm not trying to communicate (using eye movements, finger twitches, or whatever) in morse code.
For what it's worth, Morse doesn't actually work via tapping (unless you add scraping as the dash component). Tapping makes no distinction between dots and dashes; what you intend as a dash is technically a dot and a pause.
There's a parallel code specifically for tapping, called "Tap Code" : https://en.wikipedia.org/wiki/Tap_code