Shielded or not, this questions is valid for any cables category : Cat5E, CAT6, CAT6A. For CAT8 by default there is shielding !

Shielded Ethernet cables are generally more expensive and harder to install than unshielded ones due to their increased stiffness and larger diameter, which also requires more conduit space. In contrast, unshielded twisted pair (UTP) cables can deliver faster transmission speeds in environments free from electromagnetic interference (EMI). They are more affordable, easier to handle, and have long been the industry standard, making them common in most existing network installations.

Regardless of whether you choose UTP or shielded twisted pair (STP) cables, it’s important to use high-quality materials. Superior cable quality ensures longer service life, minimizing future replacement and labor costs.