The latest release of ArcPro (2.9) introduces a new Toolbox file format with the file name extension of atbx which is discussed here. Whilst I am of no particular opinion on this new development and from reading the text it appears to be a new format to future proof the toolbox, it does say "...improved performance...".
So my question to the ArcPro development team is simply what is this improved performance? Faster accessing of the toolbox by the ArcPro application or do models/scripts actually execute faster?
Please explain what this improved performance is?