The All Powerful

So in Star Wars: The Rise of Skywalker, the Sith Lord returns.  Out of thin air, he creates hundreds of ships with planet killing guns.  If he was so powerful, why not use his dark powers to blow up a planet?  Why waste time coming up with ships with guns?  This plot point seems like something out of a Bond movie.  Then the bad guy goes on to tell the hero about his weapon.  If he were as powerful as he thought he was, why did he not see that Rey would not join him?  The more you think about this movie, the more questions it brings up.  Another point.  The resistance wants to go undetected when they go after Palpatine's ships.  What do they do?  They go low tech.  Horses in space on the surface of the ships.  Yes, I know, it's ridiculous to think of.  But, it does happen.