20/20 Summary:
Build fuel depots.
Use the Moon as a staging node.
Use Mars orbit as a harbor.
Park empty rockets as assets.
Make fuel on Mars.
Send individual rockets back.
That turns Mars from a one-way trip into a transport loop.
19/20 This is not a small project.
It needs huge launch cadence, automatic docking, orbital fuel transfer, cryogenic storage, Mars ISRU, surface power, and years of funding.
But it matches the direction Starship was built for.