At least in technical writing if your English is not too good you can replace some of it with math formulae and get away with it. Ish.

Tbh my first couple research papers were brutally savaged by reviewers until I spoke to a lady at my university's Academic English department. In fact I was sent there by an internal reviewer who refused to pass my early-stage report otherwise. The lady at the Academic English dept pointed out one thing I was doing and it immediately clicked and I've only got good words about my writing style since.

Know what that One Simple Hack was? I spent my youth writing Sci-Fi, Fantasy and Horror as a hobby. So naturally when it came to writing papers, I thought, hey, I know how to write. It's like literature.

Shockingly, it is not. Like, at all! In literary writing it's basically sacrilege to write the same thing in the same words twice. In technical writing that is what you must do. Unless you want to confuse everyone about what you mean. So I was trying to make my technical writing "not boring" by not repeating the same expressions and instead finding new, creative ways to refer to the same concepts in different places, and that just made reviewers really angry because they never knew what I meant. I stopped doing that -and also generally tightened up my use of terminology- and that was it. Now every paper gets at least one reviewer that says "this is a well-written paper".

Then they brutally maul me anyway on all the rest, of course but, eh, what can you do :D

P.S. Dunno, maybe "that's a well-written paper" is what everyone says when they're looking for something nice to say before they let rip. I sometimes do it too. People do that all the time, don't they? I had calcific tenonditis and I went to a doctor and he told me "you are really brave, others in your condition would be screaming their heads off" (from the pain). And I remembered that my father had the same thing when I was a kid and he'd gone to a doctor and come back bragging that the doctor told him he was so brave, others would be screaming their heads off. I wish people didn't do that, I'm fine being just like everyone else, honest. Just don't make me doubt my mediocrity, you know?