This is not a recent phenomenon. The truth is that most scientists and engineers just plain can't write for toffee. Aside from not paying enough attention to their English
1 teachers at school, they get their writing style from their peers, so they learn to copy the writing style of their lecturers, professors, PhD supervisors and, of course, poorly written papers from the 'literature'. Weirdly this also applies to lawyers, whose whole business is words, and yet who can't write a social letter or a magazine article without it sounding like a formal legal document.
If you want proof, just read the prose of the native English speakers on this forum. Not all, but at least half of the writers have a hard time getting their point across clearly. And here, gentle reader, we are talking about a bunch of engineers who
choose to write every day on this forum, so they can't claim they're not getting enough practice.
There is no great secret to writing a paper well, good writing is good writing whatever the subject matter. Remember that you are telling a story, whether it is "What I did on My Holidays", or "An Investigation into The Behaviour of sub-10nm Transistors", it is still a story. Think about the person reading it and about what they will want to know.
Don't use a complex or unfamiliar word where a common one will do, don't use a phase where a word will do. (My personal pet hate - "at this moment in time" instead of "now".) If there are formal conventions for your field, use them - such as the typical use of "we" to describe the experimenter, even if it's just an individual - not doing so is jarring to the reader.
Keep sentences as short as fluidity will allow. Write as little as possible. By that I mean don't take three pages to say what half a page will. PhD theses are particularly prone to this disease. Someone has just spent three years of their life researching and doesn't want it to come to a mere 10,000 words. Furthermore they are encouraged to write at length even when a briefer document, perhaps with some appendices, would serve everybody better.
Professional tip: If you are writing anything that even vaguely qualifies as 'news', once you have written it delete the first paragraph. Does it still make sense? If it does, leave it; if it doesn't, OK, you can put the first paragraph back. You'd be surprised how often this works.
Learn to accept constructive criticism of your writing and get feedback. I've been a professional writer, a tech journalist and magazine section editor. In the magazine world you have sub-editors who take what you've written, clean up the grammar and spelling if it needs cleaning up, put things into house style and, most importantly, clean up any awkward or ambiguous phrasing. They are a god-send and every professional writer worth their salt gets to love good sub-editors - even if they do cut your jokes.
I find that it is amateur writers who think that their work is precious and get upset the minute a sub or an editor changes something. The latter may go some way to explaining why there are so many badly written papers out there. The journal editors probably start out their careers trying to actively edit papers for clarity. Then they run into many
prima donnas who throw a fit that their precious words have been changed. Eventually they give up and follow the path of least resistance and stop actually editing and instead become managing editors.
Writer A: "What does a managing editor do?"
Writer B: "Dunno. If you ever find out, tell me"
1 Or whatever their native language is.