Short, punchy and emotional.
When you sit down to write, it helps if you have a constraint. It can be of word count, certain words or tone. This way, you write differently.
LinkedIn is one platform that provokes that. You are on the platform for a professional reason. Hence, there is no fluff - most posts are to the point and often get shared for their stories.
One suggestion to improve your writing would be to try different platforms. Earlier, Twitter's character limit meant you had to make each tweet amazing for someone to check the next tweet.
And that's how writing should be. Your first sentence should follow the next sentence. The first paragraph should follow the next paragraph. And in the end, it should motivate readers towards some action because every writing is copywriting. You write to inform, entertain or think and then, hopefully, readers take it forward. It can be anything like a share, comment or something like skin in the game - buying a PDF or course.
There are many ideas around how you should write because it seems like a simple thing but gets hard when you have to do it every day.
Please feel free to take a pause - write to think better. And initially put no constraints. Write either one sentence or 100's. Make sure you write.
And then start putting innovative constraints. An example would be to write a paragraph of 3 sentences explaining who you are and what you do. This could become your bio for all social media platforms. Keep writing.