Three Hanja for ordering food 小 中 大 (한자) | Korean FAQ
Some Hanja are useful to know no matter your Korean level, and three of those are 소, 중, and 대.
Although you don't need to know how to write these characters, you should be able to read them and recognize them. They'll appear on some Korean menus at restaurants.
Yes, I have seen these characters and I think Hanja is very important, it allows one to make connections to multiple words. I ㅎo to the hospital for testing and hear 소변 and 대변,. urine and stool samples. Maybe a little graphic, but hanja helps a lot. Please do videos where you identify one hanja character and elucidate as many words as you can that derive from this character. It makes leaning vocabulary much easier, or a bit easier. Maybe make a contest