Robert Zubrin's Mars Direct would have got "flags and footprints" on Mars without needing something like Starship. He worked on a version of SLS in 1989 in Martin Marietta that would have cost $1B and been ready in the second half of the 90s and would be retiring soon after many successful flight to Mars (and to the Moon), but instead we got SLS and Orion so we need Starship to get anything done.