A while ago I worked with a guy that did not put effort into written communication and he was doing the marketing for the company. I would have words with the boss about this and, initially, I struggled to explain why spelling, grammar, punctuation and use of paragraphs was important.
After some thought I was better able to explain the not-so-obvious. It is all about respecting the time of the reader.
Some people don't respect the reader since they think they are important. Notably with the Ep*tein files, we have this clique of wealthy people, with few of them able to string two sentences together. Writing standards were those of an eight year old at best.
Personally I write fairly long form because I don't have ideas that I can express in glorified grunts. However, this LLM stuff is encroaching on my turf, since the likes of the guy I used to struggle with can now churn out better English than I can. That is the problem for those of us from the pre-internet, pre-grammar-checking age when written communication mattered.