Invariably, no matter how an exercise is performed, some "guru" comes along to critique. Sometimes it's well-intentioned, and sometimes it's warranted. Usually, however, it's simply evidence for how the critic is uneducated or so inexperienced that he or she doesn't understand the grand breadth of benefits gleaned from variations on a repetition.
Categorically, any movement can be altered, progressed or regressed by range of motion, resistance/loading, stability/balance and tempo. And even within these four categories there lie many subdivisions. That's to say nothing of rep, set, rest schemes, frequency of training, etc. All of these variables are subject to change based on client need, goals, ability and even mental or emotional state. The greatest all-time 200m sprinter never even dared to compete in 400m. That's how sport-specific training can become.
After I completely tore my right pectoral tendon off of the bone and had it surgically reattached, no conventional or even well-accepted unconventional rep schemes or programming yielded consistent progress. The recovery had been stochastic at best, never linear, and painfully regressive at worst.
Upon reflection, I realized that any "normal" smooth range of motion press allowed me to basically avoid the very angles where I'm most vulnerable, consequently never addressing the fundamental power leak. Thus entered a rest-pause scheme wherein I paused in the very spot where my injury felt most awkward or vulnerable. Subsequently I added partial range of motion "pump sets", again focusing on the most uncomfortable and weakest portion of my press, hoping to elicit reparative blood flow in the compromised tendon. That one single odd change, which would be missed by average people and was never recommended by my surgeon or therapists, yielded more reliable and faster improvement in one month than the prior year.
I don’t dismiss the benefit of simply doing activity. Off the couch generally outweighs on the couch. But the wide array of human movement is as big or bigger than any advanced subject. It’s a massive fallacy to equate walking or raking leaves to targeted focused training. In this case, the difference between one version of chest press and another was an entire universe. This temple of ours requires thoughtfulness, variation, intentionality.
But only because a rep isn't just a rep.