it is all important of course, after all it is a chain, so the ’weak link’ logic applies
and folks who say it is the source do have a point, the signal starts there, once purity is lost, it is never recovered
but my thinking is, as knowledgeable, experienced audiophiles, we should know how to get the source purity to a very high level, then the speakers (assumed to driven properly by amplification) are the actual ’musical instrument’ that electromechanically transduces the electrical signal to physical music that we hear... so that (and how the speakers couple to the listening room) is, to me, the most important/critical aspect for each of us to get right, and in most cases, the most difficult