You don’t scrap the idea, you fix the problem. The navy’s of the world did not scrap battleships after WWII becuase the Arizona and HMS Hood were so easily destroyed (both with a single shot), but because the Aircraft Carrier out performed it and proved to be a much more formidable weapon. And still the US used Battleships for another 60 years. You don’t get rid of technology because there is a flaw, you fix the flaw and try again. So the first Death Star was destroyed by one pilot in an X-wing with a lucky shot to a vulnerable point. What does any sane super power do? Build another without that flaw. Except that the Emperor got cocky and allowed to the location to be revealed and once they got the shield down, they didn’t need a lucky shot, but skilled pilots. So flaw fixed only for another, bigger flaw to show up.