The legal situation is rosier than you think. What you demand is already the case: content you create is copyrighted by you and can't be relicensed by anyone else without your permission. All without any agreements at all!
Now, it would be tyrannical not to give you any way to transfer rights to your creative output. So some publishers do allow you to agree to a Terms And Conditions waiving certain of these rights, or transferring them to said publishers. It goes without saying that no one would ever compel you to agree to such conditions, but some publishers might not agree to publish your work without such an agreement.
Now, it would be tyrannical not to give you any way to transfer rights to your creative output. So some publishers do allow you to agree to a Terms And Conditions waiving certain of these rights, or transferring them to said publishers. It goes without saying that no one would ever compel you to agree to such conditions, but some publishers might not agree to publish your work without such an agreement.