If those simpler life forms existed it's almost certain we've loads of traces, it's just we can't distinguish them from noise because they've degenerated so far

If those simpler life forms existed it's almost certain we've loads of traces, it's just we can't distinguish them from noise because they've degenerated so far. It's like looking for fossil structures in crude oil - crude oil is remnants of life but is mainly long carbon chains. Very little if any structure remains. Analogy #2: your great-great-...-great grandparents of 10,000 years ago unquestionably existed, but show me any direct evidence they did. You can't. All signal is gone.