If Microsoft Word agrees with all your sentences, perhaps you're not sufficiently good at writing. Or perhaps, by restricting yourself to what your grammar checker thinks is good language, you're holding back your potential, because the right way to express your thoughts is more poetic than you thought. And for all that's good, don't mangle your pretty words, your very own words, by putting them through a language model.
Orthographic errors are supposed to be bad because a non-standard way of stringing together words is harder to understand than a standard one. Fair enough. The same goes for stylistic errors, which are of course also readily pointed out by many kinds of software, nowadays. But what if, and this is just wild speculation, you understand better what you intend to say than a pile of regex and matmuls?
Bad amateur artists, confronted with the subpar quality of their work, will often defend themselves with: "But that's just my style!"
Relatedly, there is only a limited number of weirdness points to spend on your unusual writing style before the reader declares you a crank, unless you can convince them you're avant-garde of course. So maybe I'm just a bad writer and salty that I don't understand grammar and style, but what I can say for sure is that I love bad amateur artists, and wish there were more of them. Good or professional artists, even better. I want to read what you wrote.
Look at this graph. It shows the ratio of non-standard spellings to standard spellings of 840 words from the big NGram book corpus as a function of time. For each year of publication we sum up all occurrences in the word list of the correct spellings as per today's dictionary and divide by the sum of common incorrect spellings of the word. There's a lot going on, but we focus on the decline of non-standard spellings in books starting from 1983. Anything come to mind that started around that time? Spell checkers were invented in the 60s, grammar checkers in the 70s, but the year 1983 marked the birth of our prime suspect, MS Word. What has happened here is the halting of innovation. Everybody is converging to the same way of writing. We are forever locked into "airborne" even if "airborn" makes more sense. English spelling is so awful that we make kids spell for sport (try and talk to a Hungarian about spelling bees, it's great), and it will never change. It will never change! The lock-in is too strong. How crazy is that!
Spelling is arbitrary and not so important; we're just using it here because it's easy to measure and spell checkers are more widespread than grammar and style checkers. But just imagine the damage that an opinionated style checker would do if it were as ubiquitous. Language is still universal and you can technically think any given substantial thought in any style, but you will be quicker to think certain things if the style is right.
In the good old days we had a constant stream of quality words coming out of AAVE. But recently, many common-use English neologisms have been coined mostly by horrible internet cesspools of bad opinions. This is because those cesspools are run at higher than room temperature; people there are nonconfirmist and they write short, not very prosaic text interactively, without any goal or structure. The source of new language doesn't have to be online twats: Let's all make some words, folks.
Mathematicians are really powerful, in part because of their amazing ability to invent language all the time. Sometimes it even leads to rare natural language grammar, like "subspace preserved under addition". All four words are math inventions with a precise meaning. Take a page out of the math book and dare to get freaky with the language for whatever you're doing.
The squiggly line is not your boss. If you have one in your texts, it means you're moving humanity forward, and people should be thanking you for it. May they scoff at the wording, or find it great — whatever the case may be, you just mutated an allele in the evolution of language, that your descendants will see turn into a whole species of its own.
And I'll keep starting my sentences with conjunctions, tee-hee!