You could make a case that the 4th amendment is dead, since nobody has seriously fought the abuse since the Patriot Act. The Dems and ACLU have done a 180.
Barr's efforts suggest that there is hope. But if nobody backs him that too will fail. Maybe it's too late to save the Constitution. Just getting FISA under control would be extremely difficult, especially with Roberts in charge.
Maybe you think I am getting off topic here, but I think it all connects.
You call it abuse, the government calls it protecting the public.
Barr's inquiry goes to use of the government apparatus (keep in mind the attack on the election was a made-up accusation), in cooperation with the press, to turn an election. That's a narrow abuse. IOW, if the government want to get YOU, outside of election process, Barr isn't looking there.
As for FISA, it is not a restriction on government abuse, it enables government abuse and pays the players (the executive and the courts both) a bonus to perpetrate it.