The "doesn't impress me" part was intended as a joke
Comparing the energies of the microquasar's gamma rays to the kinetic energy of a flying mosquito was also intended as a joke.
What really matters here is the density of energy, and it is really enormous. For comparison, a blue light photon carries an energy between 2.50 and 2.75 eV while for the microquasar's gamma rays each photon carries around 25 TeVs, that's not twelve but THIRTEEN orders of magnitude above.
All that energy concentrated in such a tiny particle. That's really impressive!!!