I could not agree more.

I would only add that a well-written text usually respects these three properties: Adequacy, Coherence and Cohesion.

Adequacy
-What is the genre of your text? How technical is your writing?
-Have you clearly outlined your purpose? Are you consistent with it? Who are you writing for? Do you think your target audience will understand what you are saying?
-Does your text show good spelling and typography (headings, quotes, font decoration)?

Coherence
-Did you choose only the necessary amount of information?
-Is your speech well organized? Have you previously schematized the flow of ideas?
-Do you present the information logically and congruently (repeat when necessary, reveal new ideas progressively, do not contradict yourself, show the relation of the topic with reality)?

Cohesion
-Do you make good use of grammar?
-Do you make sure you do not have hackneyed words and phrases.
-Do you use synonyms and alternative names intelligently?
-Do you use paragraph and sentence connectors?
-Do you make good use of punctuation marks in your text?

Also, I want to mention that sometimes it is important to show authenticity and trustworthiness as authors, especially if you claim to be a physician or something like that. While we don't force people to reveal their identity, those who do get better results in this regard, as it's easier to trust someone who can decently demonstrate that they are a medical doctor and that their posts were made in the context of their profession or expertise. Let's not forget that there are many scammers and abusers on these social media networks.