Learning the Korean alphabet (Hangul) can be done quite quickly, it's only about as many "letters" as the English alphabet!
Remembering the words is a bit more difficult though, especially if you don't know a similar language. Have been using Anki and my own app for that: https://game.tolearnkorean.com/
Meanwhile, "Korean writing is so easy and logical you can learn it in no time at all" has become a meme to the point where I suspect the number of people who've been exposed to the meme and don't remember a single character might be larger than the number of Koreans who've heard about the tongue shape thing and still remember it.
Also, ㄹ is obviously anatomically impossible for human tongues. It does however closely resemble similar letters in some Brahmic scripts. I'm partial to ʼPhags-pa ꡙ https://en.wikipedia.org/wiki/Origin_of_Hangul#%CA%BCPhags-p...