This is such an important step forward as we start to understand the 2nd order implications of AI and how it will change UIs in the future.
We used to have to allow + review 3rd party plugins for software so that people could customize it, but when the cost of development is near-0, we can simply hand over the development reigns to customers.
Yes -- the future of SaaS looks more like a system of record, on top of which AI serve what's needed on the fly based on what the customer needs.