head to head
Descent asks more than Red Dead Redemption 2, and the gap is execution.

Execution · Practiced Mastery
Pioneering six-degrees-of-freedom shooter through robot-infested mines.

Execution · Practiced Mastery
A cinematic open-world western leaning on shooting feel and atmosphere.
Descent leans Execution (Practiced Mastery); Red Dead Redemption 2 leans Execution (Practiced Mastery).
Descent leans clearly harder on execution.
Descent
Full 6DOF control and aim under disorientation is the test
Red Dead Redemption 2
Gunplay and Dead Eye reward aim and timing.
Red Dead Redemption 2 leans a little harder on reads, though the gap is small.
Descent
Scripted robot behaviors, no adaptation
Red Dead Redemption 2
Enemies use scripted AI patterns, not adaptation.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Descent
Mine layouts fixed; ambushes surprise only once
Red Dead Redemption 2
Some hunting and weather randomness, lightly hidden.
Descent leans clearly harder on optimization.
Descent
Route memorization and weapon economy reward optimization
Red Dead Redemption 2
Loadouts and routes solvable but loose.
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.