Why would you need dmesg if you get your hw errors over the tracepoint?

Redundancy is a good thing when talking about mission critical systems.  dmesg
may be feeding to a serial console to be logged and analysed on another system.

The tracepoint data goes to a process on the system experiencing the errors. If the
errors are serious (or a precursor to something serious) that process may never get
the chance to save the log.

-Tony