Focus on short sentences and simplicity is an American trait. It is a bit different with UK English. As a native Portugese speaker, I spent my time before the US doing exactly the same as the author, I could write well structured prose by the time I was in 5th grade. I grew up with a dictionary. My mother would come back from work and ask me for the list of "difficult words". The expectation was that I spent time reading and would have found some new words, looked them up and now needed to sync with her to see if I got the correct meanings in the context where I found them.
Then I moved to the US and noticed that even the books were sort of written in a way that required no extra effort. The English I learned while playing RPGs (with no speech at the time) was enough to read most books from the library and a dictionary was only needed occasionally. And everyone basically just knew the same set of words, youth and adults alike. I also noticed that US English has a distinct tendency of making up new words that are simpler and more intuitive than the original expressions. It turns things into verbs. This is why people Google, Tweet and Vibe.
Then I went to an Engineering College, and it teaches us to distill everything into it's simpler fundamental components. I like it, and I now want people to be as direct as possible.
As a non native english speaker, I've always had to speak and write better than native speakers, and always had to tolerate the "You speak/write really well, where are you from?". Today they no longer ask, AI is their answer and they judge accordingly.