Keep in mind that some tools that we use daily in marketing (and not only) are just ideas that stuck.
As such, it is good to periodically review them to make sure that they are still useful and that people using them agree on what they are for.
The funnel is such an idea.
Everybody uses it and talks about it all the time. Yet even within the same organisation, it is usual to have different people look at it from different angles, defining different stages in different ways, and generally using the levers for somewhat contrasting purposes.
So, asking what a visitor is, what a lead is, what qualification means, and agreeing on the process that moves traffic back and forth is a great place for teams to start. And to go back to whenever it makes sense.
Without this conversation, chances are that you are all focusing on separate parts. And that’s not how the funnel gets going.