Let me put this a little simpler for you.
A cage isn’t the end all be all to vehicular safety.
Its a key element.
When combined with other necessary elements, they work together to save lives, they best they possibly can.
Think of it as a puzzle piece, you cant complete the puzzle without all the pieces on the table.
This isn’t me pretending to knowing everything. Its me restating the obvious.
By the way, what is your point anyway? that he is better off without any added safety equipment in a convertible car with 1000whp???