China’s Mars Rover Has Not Moved Since September, NASA Images Revealed

Even getting signal back from Mars is a triumph. NASA are careful to define mission goals low-bar because of the blowback from the inevitable risk side of space exploration.

Wikipedia says only 19 of 38 mars landings have succeeded.

Sure, a huge amount of success in the NASA/JPL experience is both depth (they've had their train-wrecks in the past) and spend (they can and do make sure everything is checked twice, checked thrice) but also.. there's a bit of luck. If any of the Mars robots had fallen into the wrong shaped crack, had more than expected dust land on the PV, lost link at a critical juncture and burned battery trying to regain lock...

Or like the british, spent too much on "blur" theme songs, designer colourchart checksheet and general "cool" and not enough on debugging that landing sequence... (to be fairer to my home isle, a lot of what happened to the lander was bad luck: it may have landed hard, two of 4 PV maybe failed to deploy and it's radio comms could have been blocked)