I still think "I-32" (DFW-Amarillo-somewhere on I-25) is good enough for Oklahoma. It reduces the distance from Oklahoma City to Denver over the current all-freeway route, and it doesn't require backtracking if Colorado Springs (or Pueblo), rather than Denver, is your start or end point. It also serves Wichita Falls, TX along the way,
The DFW-Amarillo "I-32" route does little, if anything for motorists in Oklahoma. It's 100% irrelevant to anyone in Oklahoma near or North of I-40.
The only drivers from Oklahoma that would derive any benefit from an all Interstate DFW-Amarillo segment would be in SW parts of the state, like Lawton or Altus. Motorists driving to the Denver area from places like OKC
or Tulsa would have to continue either driving on existing routes to Boise City or clear up to Salina, KS. An improved,
4-lane divided US-287 between Boise City and Limon would be safer, but drivers from OKC have to bounce around the path OK-3 takes over to Boise City to get there.
US-287 definitely needs to be upgraded fully to Interstate standards between DFW and Amarillo. But that should not be sold at all as some kind of benefit for Oklahoma motorists or drivers going through Oklahoma. It's a different corridor.
As far as suburban traffic in OKC and Denver, I guess it all depends on what parts of the cities one is traveling from and to. But I-25 between Denver and Colorado Springs is under construction so that could add time if someone were taking the more “direct” route.
CDOT (or more like the CO state government) is pretty bad at under-estimating traffic capacity needs on its highways. I-25 has gone through pretty much a complete re-build through Colorado Springs over the past 20 years. The end result: no more than 3 thru lanes in each direction. Ugh.