If the M1's emulated x86 performance is this good, why didn't Apple showcase this sort of comparison at their launch announcement? This seems like something that would have assuaged concerns about the apparent tradeoff of switching silicon. That is, it seems there is very little downside, especially if the M1 is more power/heat efficient.

A comparison like this would have demonstrated this point more definitively than the many graphs Apple showed that were conspicuously lacking axis labels.