Why are you looking at McDavid's D+1-4 and comparing it to Matthews' D+0-3, especially when that's not either's pre-signing period? What McDavid did between 2016-2019 is irrelevant. What matters is what both players did during their respective pre-signing periods, and I have provided that for you, and even adjusted it based on league average scoring rates, at your request. Nothing changes the fact that Matthews was comparable to McDavid at time of signing.
Matthews was not the better primary point producer
Yes, he was, as I showed. He was the better primary point producer at both ES and PP, regardless of whether or not we adjust for league scoring rates. He was also trending as a generational goal scorer, and still is.
Also using league adjusted stat is pretty flawed in this scenario as the increase in goal scoring wasn't uniform at all as despite the massive surge in elite scoring, league average actually "only went up" by around .25 goals despite. So the changes were actually more beneficial to skilled elite players instead of the 40 point grinder, hence why I find it more useful to compare these guys relative to their peers. I.E. whatever adjustments you made is a gross understatement of the actual reality really is
No, the adjustments I made were not a "gross understatement" of the reality. They are way, way more accurate than looking at numbers of players above some arbitrary threshold, which is literally useless.
The reality is, the difference from the things you said we needed to account for like equipment changes, were the same impact for everybody, but that impact was minimal; way less than people around here seem to think. League scoring rates didn't actually change all that much. As explained, more players in the top-end bracket is not a result of league scoring changes; they are a result of a mix of internal factors, such as an influx of talent, and evolving coaching behaviours, like line composition and increased TOI for stars (which is why it's so apparent in top-end raw points).
You're basically asking current stars to be paid less because current stars are taking on more responsibility than past stars. That's so backwards I don't even know what to say...
Besides the reasons why McDavid was so much ahead of Matthews in secondary assist in the 1st place was because of how much more impact he has when he is on the ice and how much better he is at controlling the game.
If that was true, he'd be getting more primary points, not less primary and more secondary... They had very comparable on-ice GF/60 at both ES and PP, especially when we consider that Matthews had to deal with split PP units for 80% of his pre-signing sample.
Secondary assist is still a valuable stat
Highly debatable. Most studies on the "value" of a secondary assist place it somewhere around 5 times less valuable than a goal/primary assist, and they're not nearly as repeatable.
I mean Corry Perry's primary ES stats from the shortened 2013 season until the 2014-2015 season (3 seasons) was actually .17 higher than Crosby's while also having a p/60 stat that was good enough to land him in 3rd place (better than AM) during that time period, yet not even Cory Perry himself will tell you that he was better than Sid during that period in time when everyone regarded Crosby as the best forward in the world. PRIMARY POINTS IS NOT EVERYTHING.
Nobody said primary points are everything. That's why I'm saying Matthews was comparable to McDavid at that point in time, not Matthews was way better than McDavid. But they are also not nothing. They are part of the picture, just like points.
As for Crosby and Perry, Perry was quite good back then at ES. He also played with Getzlaf, who placed just ahead of him in ES P/60, which boosted both of their ES totals relative to Crosby, who didn't play with anybody like that. Crosby was also just coming off his years of major injury/concussion problems, and had barely played in the previous 2 seasons. Crosby was also better on the PP, which again, you keep leaving out...
PP Primary points/60, 2012-2015
Crosby: 4.08
Perry: 2.62
Overall, Crosby was still the better point
and primary point producer during those years.