There are more than 50,000 characters in Chinese languages. What is the reason behind it? Are all 50,000 characters in use?
Chinese may have many characters, but many are not in use such as some 甲骨文 and such. Many (pretty much all) Chinese characters are from drawings, with the exception of new ones such as 'biang' . Your average Chinese adult that graduated college only needs to know around ~3000 and experts know ~5000 or ~7000 if you are really good. Some characters become redundant as they can be formed by others.
Chinese character each has its own special meaning. Even though they sound the same, but they mean something different. This is not scholars back then has nothing to do so they try to complicate things. We have to look back in time to know why
Before the modern Chinese characters were born, we have a bunch of drawing like characters called oracle bone script (甲骨文). Because it is very similar to the reference object, it is understood by many people from different ethnicity. China has a very diverse population, with 56 ethnic groups. I'm sure they have more back then and each ethnic group very likely speaks their own language as well
Oracle bone script > seal script > clerical script > semi cursive script > cursive script > regular script (modern Chinese characters)
As time goes by, more and more characters were added to express things that weren't being expressed before. However, these new characters have maintained their relation and meaning within the character itself, so that it will remain relevant to people who come across it without knowing the character.
For example, 木 means wood. 林 means woods. 森 means.... you've guessed it, forest
Above example shows 2 categories of Chinese characters, singular component characters and multiple component characters. Singular component characters are characters that describe themselves and they are usually strongly linked to those ancient characters. Multiple component characters are characters with multiple underlying meaning in it. 林 and 森 are great examples of this form of character. And more 95% of Chinese characters are multiple component characters. So once you know the meaning of all base characters, you can roughly guess the meaning of most multiple component characters without knowing how to pronounce them at all. This is the wonder of Chinese characters
Apart from that, Chinese characters and going back to older form of scripts, they were designed for communication across many many languages. Any person who knows what fish looks like, knows what a drawing of fish represents. So, a logograph that is derived from it is easily understandable by large part of the population.
Additionally, Chinese bureaucrats make use of this system to help communicating and managing more population. This is why Chinese characters (漢字) are still relevant in Korea and Japan till this day. So, the second wonder of Chinese characters is that it is understood by many ethnic groups despite their language barrier, which today we have categorized these different languages as Chinese dialects