Ok, let's look at the numbers:
Cooper McLaurin
Targets 112 114 1.78% more for McLaurin, not statistically significant. (3% is the normal rule for statistical significance) Essentially the same
Receptions 80 73 9.58% more for Cooper. Advantage Cooper.
Yards 942 1,001 6.26% more for McLaurin. Advantage McLaurin.
Tds 5 3 66.67% more for Cooper. Advantage Cooper.
So one stat the same, 2 to Cooper and 1 to McLaurin.
Now value, sure, McLaurin has that by far. But first of all their contracts were set before this season, nothing we can do about it.
As far as quarterbacks, McLaurin has had Smith for 7 games, Cooper had Dak for only 5. Smith's no slouch, no Brady, etc. but he's a veteran, same as Dalton. No advantage for either Cooper or McLaurin.
Cooper's being wasted on this team without Dak, and without a good o-line to give his quarterback time to throw. This year is an aberration, almost nothing about the Cowboys is anywhere near normal, let's not judge either player by this year alone, next year will probably give us a clearer picture. I have McLaurin on one of my fantasy teams, so I'm not anti-McLaurin. But he's only in his second year, won't be able to judge him vs Cooper until he has a few more years under his belt....