Yes, exactly, human languages are complex and in my opinion Unicode used to be on a good track to tackle these complexities. I just think that nowadays they are not doing enough to help people around the world solving these problems.
The elephant in the room is Han Unification but there are plenty of other issues. Here is one of my favourites from another thread just two days ago.
https://news.ycombinator.com/item?id=44971254
This is the rejected proposal.
https://www.unicode.org/L2/L2003/03215-n2593-umlaut-trema.pd...
If you read thread from above you will find more examples from other people.
can you describe a few examples? what are you missing? or maybe are you aware of something they rejected that would be useful?