Why transporters are not an effortless superweapon

Are transporter weapons too energy-intensive to use regularly in combat?

Energy matters, but defensive shields and dampening fields are the stronger explanation for why transporter attacks are not always available.

The prompt suggests that transporting weapons may consume too much energy to be routine. That explanation works only in part. Once a transport capability exists, opponents have a powerful incentive to develop shields, dampening fields, and other systems that disrupt it. Transporters would still be weaponized whenever access was available, while countermeasures would keep that opportunity conditional rather than universal.