The full spectrum can be saved by various tricks.
Disputes on this topic can continue indefinitely. And it's useless.
I did not say that the spectrogram is a panacea. I had in mind some problematic areas with breaks, which are of concern. Here is the screenshots of the spectrogram 2 different encoders AAC 160 kbps. On one of them there are problematic plots, I singled out them.