In Denmark we use upper case pretty much as you do in the USA.
I wouldn't be without it.
It adds flavor and clarity to the written language.
In Germany, our neighbor to the south, they use upper case for nouns
- we did that in Denmark until AD 1956
and for me that adds an extra vigilance when reading and writing German.
So, please, enjoy what upper case does for you as an American

Chinese uses characters. Some are based on pictures, others aren't, and there is a whole system to combine them to make new characters as well. One of my favorites is 木 which is wood or tree. Put two together and you get a forest 林, and another one on top for a huge forest 森. When China went Communist they simplified the system which results in less strokes of a pen and are easier to read as they are now less complex. But places like Macao, Hong Kong, and other countries that use Chinese characters, did not simplify theirs.

Japanese uses Chinese characters but also made two alphabets. The alphabets are not vowels and consonants, but each letter is a combined consonant+vowel which leaves you with a ton of choices. That is why Japanese is always consonant vowel, consonant vowel, consonant vowel. A singer name as an example is Utada Hikaru. (Edit: Oh, but Utada starts with a vowel. Hmm.) You don't get double consonants and don't get double vowels (to the best of my knowledge but I didn't get far in learning Japanese). There is no capitalization system.

Korean used to use Chinese characters but that has nearly completely disappeared from current use. In use is an alphabet with separate vowels and consonants. You can double up some characters to make harder sounds like ㄷ and then ㄸ or ㅂ and ㅃ. Unlike most alphabets, the Korean alphabet can cluster letters together into groups of 2, 3, and 4. This means the name of the country is 한국 and not ㅎㅏㄴㄱㅜㄱ. For better visuals of these clusters, you can check here (https://centers.ibs.re.kr/html/living_en/overview/korean1.html). The site isn't finished but will be by the end of the year. There is no capitalization system and spaces are optional in names of companies. So the main basic science institute is 기초과학연구원 but with spaces it would be 기초 과학 연구원. The lack of spaces really was difficult for me to get over for names of businesses as I had no idea where to break up the words, but in sentences there are spaces. Historically there were no spaces.

For some additional fun, find out what year it is in different countries. And I don't mean solar calendar and lunar calendar. China has a separate year, Israel has a separate, as does North Korea, Thailand, and Taiwan too. Iran has not only a different year, but the months are different as well - but I don't know it well enough to say more than that.

Edit: Little more information under Japanese and mention of years and calendars.

@Seoulpowergrid

What an informative pair of posts, thank-you!

Your point about the definite and indefinite article is one I can sympathise with. I taught myself some Gaelic (Gàidhlig), and that language has no article at all for the indefinite, and the definite article is "a", or "an" before a vowel -- very confusing!