I also want JS to continue building that way but to your point, I'm sorry but Price-for-Walker isn’t really comparable to the quarterback situation.
Running backs are replaceable. You can draft a guy like Jadarian Price, plug him in (alongside Charbs when healthy, Wilson, Holani, etc.) and the offense still works. Remember that early on last season, the running attack wasn't all that effective but it was because we kept doing it which forced opposing defenses to have to honor the run against us which enabled our Passing offense to flourish. Because of that, the system and supporting cast did carry a lot of the load.
Quarterback is different. If Darnold keeps playing at a high level, the entire offense and the franchise’s contending window are already built around him. Moving on from a proven top-10 type starter for a developmental guy is a much bigger risk than swapping one productive (though somewhat-injury prone) RB for another.
Milroe’s young and has time, which is great. But stating that we have “3 more years to evaluate” still means you might eventually have to walk away from a high-level QB just because the kid is ready.
That’s a way tougher call than letting Walker walk and drafting his replacement. Letting Walker walk and drafting Price is smart roster management at a replaceable position.
Forcing a QB transition the same way is potentially punching yourself in the face at the most important one.