Here’s another “incredibly fortunate” thing about the Cambrian explosion and about evolution generally.
Astrobiologists think they may have found where life came from — cyanide in meteorites!
There are many solid, trustworthy inferences in modern science, but there are those that are not very trustworthy at all.
It’s circular: “Because evolution innovates things, it will innovate things if given the opportunity.”
The basic thesis of TPP is that the best places for intelligent observers are also the best places for observing.