Examining what it would take to realistically build an Imperial Star Destroyer, it was estimated in 2016 that such a vessel would cost $636 billion USD. Using then-current technology and naval vessels as a reference, the ship would weigh 4.44 billion kilograms, generate 146.5 gigawatts of power, and its engines would produce a combined total thrust of 3.5 million newtons. However getting the parts into space to construct the Star Destroyer would require an additional $44.4 trillion USD in launch costs, suggesting that asteroid mining and refining technologies would have to be developed first to make it more economical.[18][19]
Weapons of terror tend to be messy. There were railroad guns that could hit Paris from seventy miles but couldn't accurately target a spot within Paris, so it was used to stomp civilians.
Nukes are terror weapons in that they dont just kill the target but plenty of territory around it as well, which is an exclusion zone for a while.
I can't speak for the Star Destroyer but the Death Star super-laser is clearly a mining tool used to crack open planets to get to the gooey center minerals. It can be used to annihilate a planet, but that's usually a waste of real estate.
Yamato is also a Wunderwaffen, where the Star Destroyer is a mass produced system actually meant to wage war and is battle proven by its years of service and the lessons learned from its Clone War predecessor. Too bad they still stuck the bridge on top so it'd still look like the USS Texas though