ZIRP was 2008 to 2022? The 2010s were calm and collected, zirp-mania gripped us through the pandemic. You cannot compare 2011 and 2021. Totally different environments.
Whatever you want to say the current market is, it's nothing like the early 2010s.
The ZIRPmania of 2021 was certainly dependent upon what came before it but it wasn’t a natural outcome, it needed the economic chaos of the pandemic, it would not have happened without the pandemic.