In my opinion, yes, more indirectly than directly. LLMs were trained to optimize their response for everybody, and lowest common denominator sentence structure is spaghetti writing. But more concerning, LLMs are subconsciously teaching people how to write. It's becoming harder for people online to pace their writing and build up to a conclusion without resorting to spaghetti writing.

I do it more when typing on mobile. Ain’t nobody wants to read (or try to edit) paragraphs almost as long as their screen is tall.

Coming from texting is a good thought, but I assumed it came from LLMs "ingesting" all those rah-rah LinkedInfluencer grindset articles. Every time I read something with the single-sentence-per-line, or maybe even single-word-per-line style, I'm reminded of LinkedIn, and I also start suspecting LLM-generated text.