1. Flawed warrant applications were made
2. Those flawed warrants revealed a criminal conspiracy at the highest levels of a presidential campaign, that has sent many people to prison. It is documented very well in the Mueller report. Further good background is the Crowdstrike report on the DNC hack.
This is gaslighting of the worst kind. The procedural errors made by the FBI while investigating the crime pale in comparison to the crime itself and this is a deliberate attempt to conflate the two. I have read Greenwald for the better part of two decades when he was writing independently on a Wordpress site and I have no idea what has happened to him.