If you build Notion with the same approach as the other tools, then it won't be much different.
The pattern is consistent: a new tool is selected, configured, and adopted with initial enthusiasm, only to be gradually abandoned as the old chaos reasserts itself within the new interface.
The tool was never the problem. The missing element was systems thinking, which should have occurred before selecting any tool. That means mapping the process of how work moves from client request to completed delivery, where accountability lives, how handoffs happen, and then designing the tool to support that process rather than hoping the tool does it for you.
Notion is particularly well-suited to this work because of its flexibility. But flexibility without design produces the same result as every previous tool. The difference isn't the tool. It's the approach to implementation.