In-universe, the “power use” argument seems strongest. Even if you could generate unlimited power, you can only distribute so much power under nominal use conditions and even under extreme use conditions like combat, do not maxing out with the included power load of shields 24/7 seems practical.
But out of lore, and just speaking practically, declaring “Shields up!” Was a critical narrative device for audience exposition purposes.
The crew needed to telegraph to the audience how significant something was or how dire something was, and I think nearly all shield chatter served that purpose.
In-universe, the “power use” argument seems strongest. Even if you could generate unlimited power, you can only distribute so much power under nominal use conditions and even under extreme use conditions like combat, do not maxing out with the included power load of shields 24/7 seems practical.
But out of lore, and just speaking practically, declaring “Shields up!” Was a critical narrative device for audience exposition purposes.
The crew needed to telegraph to the audience how significant something was or how dire something was, and I think nearly all shield chatter served that purpose.