  I point out similarities between point-symmetric X-ray morphologies in
cooling flow groups and clusters of galaxies, which are observed to be shaped
by jets, and point-symmetric morphologies of eight core-collapse supernova
(CCSN) remnants. I identify these similarities by qualitative eye inspection of
multiwavelength images. I use these similarities to strengthen the jittering
jet explosion mechanism (JJEM) of CCSNe, which predicts that the last pairs of
jets to be launched by the newly born neutron star might shape some CCSN
remnants to point-symmetric morphology. The point-symmetric morphologies in
both types of objects are composed of two or more pairs of opposite bubbles
(cavities), nozzles, some clumps, small protrusions (termed ears), and rims.
The typically large volume of a CCSN remnant shaped by jets implies that the
shaping jets carry an energy comparable to that of the ejecta, which in turn
implies that jets exploded the remnant's massive star progenitor. The
morphological similarities studied here add to the similarity of CCSN remnants,
not only point-symmetric ones, to planetary nebulae shaped by jets. Together,
these similarities solidify the JJEM as the main explosion mechanism of CCSNe.
I consider the identification of point-symmetry in CCSNe, as expected by
jet-shaping in the JJEM, to be the most severe challenge to the competing
neutrino-driven explosion mechanism. I reiterate my earlier claim, but in a
more vocal voice, that the main explosion mechanism of CCSNe is the JJEM.
