I'm going to go against the grain and say that posting on LinkedIn is actually a good idea. It builds your brand and that is valuable. As cringe as it may be, it puts your name in the working memory of people who might be useful in your career (recruiters, hiring managers, potential collaborators, etc.)

I also think this goes for all the analogous versions of LinkedIn (like Tiktok if you're a creator, or Instagram if you're an artist). Not having a place to show off your work will slow down your growth and progress.

I'm a fairly private person but I've been considering the opportunity cost of it, and I think it's pretty high. Overall +EV: the risks of putting yourself out there are low (i.e. strangers think you're cringe), but the benefits are very high (new jobs/opportunities). I might just start embracing the cringe.