It's definitely a little more than just a trace viewer.
As the page reads, it is a time traveling debugger. You can jump back and forth between different snapshots of time during the execution of your program. It's neat because for compiled languages like rust doing something like this is more advanced.
That is exactly how trace viewers have been used with time travel debuggers for literally, and I do mean literally, over 20 years.
You click a point in the trace, you jump to that point in time. That has been the standard integration for decades.
I was under the impression that with a trace viewer you would do that after the execution of the program has finished. Learned something!
It's both. It is a trace viewer, but they instrument native code to emit logs of its operation, e.g. calls and returns, similar to what the recent non-performance-counter rr branch does. Except for some reason it's coupled to a specific GUI and a specific language instead of being a general purpose tool like RR is.
The tech industry is getting stupider and hype-ier as it implodes.