This not an argument about "performance per watt" or "efficiency" it is just for performance. If Apple had allowed for the increasing thermal requirements for the Intel chips, Macs would run just fine.
Apple didn’t build systems in a vacuum, they would consult well ahead of time, align with Intel’s release schedule and, if Intel says, “We’ll definitely be able to ship on time, in quantity and in a form factor that you’ve specified”, Apple can do nothing but build the enclosures/motherboards specified and trust Intel’s roadmap. However, Intel during those days RARELY hit their goals (well, they’re still not hitting their goals, but anyway
and in some cases shipped CPU’s so buggy, Apple was logging more bugs than Intel’s internal testers. All vendors WANTED to ship i9’s that used LPDDR4, but no one was able to because Intel didn’t include that capability. Other vendors just molded a different plastic body, in most cases thicker and heavier (because of the larger battery required) and crammed in desktop DDR. Apple, due to Intel missing their roadmap, was stuck with speed bumps.
Apple COULD have allowed for the increasing thermal requirements IF Intel specified on their roadmap that there were going to be increasing thermal requirements.