why don't japan add "L" semiconsonants in their volcanulary to avoid L/R confusion
making "L" phonemes isn't hard with a little bit of practice. try making a "Da" (だ) with your tongue, now use only only the tip of your tongue while excluding the sides of your tongue from the roof of your mouth, try saying "Da" in this method, congrats, you've learned how to make a "La" phoneme