I have never read a good post on LinkedIn. Not one, ever. For me, it has always been motivational quotes and self-applauding stories.
You do have to adhere a bit to the "house style" (lots of exclamation points! And emojis! And "shoutouts"!)
The real problem is LinkedIn is happy to ignore my own posting style in figuring out what I want to see. Everybody else wants chicken soup for the spul nonsense so that's all I get served.
It's already hard enough to find genuinely useful blogs and content, burying it in pap and self-promotion is algorithmic malice.
When you do neither, and when you actually meet and connect with thoughtful people, you can find thoughtful content.