Because software and "information technology" generally didn't increase productivity over the past 30 years.
This has been long known as Solow's productivity paradox. There's lots of theories as to why this is observed, one of them being "mismeasurement" of productivity data.
But my favorite theory is that information technology is mostly entertainment, and rather than making you more productive, it distracts you and makes you more lazy.
AI's main application has been information space so far. If that continues, I doubt you will get more productivity from it.
If you give AI a body... well, maybe that changes.