A ‘Rube Goldberg’ machine technically ‘works’ too.
Look at how Elon Musk landed those two boosters on earth.
They used a lot of moving parts whose weight was useless after landing, which limited useful payload.
What are you arguing about?
If they can hover, lower a payload by cable, and then disconnect the cable and accelerate away, then they could have just landed.
All those steps introduce potential issues and risks, and involves weight and effort NOT contributing to useful payload.
You have it exactly backwards. By not landing everything, they saved the fuel, extra motors, etc it would take to land non-rover stuff.
What would you have them land? Some huge capsule? A large rigid-mount with overhead landing engines? Then some more mechanical parts to get out of the capsule or to jettison the landing rack? Mass, mass and more mass.