You are arguing pantyhose (one size fits all).
The right technique is
1) one that is possible. Sparky (Peter) obviously cannot have an emulator hanging 5kV above ground. It is darn difficult to debug a system using all communications resources for critical signals with printf();
2) one you know.
3) one that fits the problem you are chasing. If you can not stop the process and have meaningful results, a breakpoint does not say much, if you are debugging an ISR, printf() is not of much help.
4) Non-Hobbyists only: one that gives a decent ROI, if a @400 Ceibo EB-51 saves you 5 hours, you should have it, if a $3000 ICE saves you 50 hours, you should have it.
5) one that is fun.
Erik Malund