I agree, it’s your choice. But, if you want to help others, you also have permission to share your work.
You probably don’t think your work is valuable but someone is waiting for your unique perspective. It doesn’t need to be perfect; nothing is.
You can also write publicly but for your future self, which drops the barrier to entry.
Of course you’re allowed not to write or not to share. It’s not for everyone. But don’t let fear or self-doubt stand in your way either.