"The #PTAB implemented discretionary denials, among other changes that made it harder to access IPR and made IPR a more expensive and complex procedure. And, unsurprisingly, the AIA’s benefits began to reverse—mostly to the benefit of NPEs." https://www.patentprogress.org/2021/11/16/the-pat-signal-is-going-dark-senator-leahy-wont-seek-re-election/