The biggest issue is that the interchange between speed and time is not linear. So that graph doesn't make sense as displayed.
At a minimum you have to understand that the time scale on the side of the graph is not linear, but rather exponential. And graphs with exponential scales are not easy to understand.
Making it worse is that there are other things that can slow down time - namely acceleration.
I wasn't really criticizing you as much as the concept of describing relativity as a tradeoff between the two. I don't think that helps enough to overcome the misunderstandings it can cause.
The biggest issue is that the interchange between speed and time is not linear. So that graph doesn't make sense as displayed.
At a minimum you have to understand that the time scale on the side of the graph is not linear, but rather exponential. And graphs with exponential scales are not easy to understand.
Making it worse is that there are other things that can slow down time - namely acceleration.