But the Stasi was a secret police in a totalitarian state, not a liberal democracy. Apples to oranges. Good faith actors in government, with intense oversight from elected officials, makes your concerns null and void.
Because government agencies have such a good track record of ensuring they only ever contain good faith actors and would never hide things from oversight, and such oversight would never be done by people willing to look away if it "hits the right people" or some nonsense like that.
A liberal democracy has the ever present risk of devolving into a totalitarian state (just look at the Weimar republic or Argentina in the 70s). We must hedge our risks, fight tooth and nail so it doesn't happen, but when it eventually happens, better not to leave a well oiled, powerful machine ready for the totalitarians to crush us.
