Comment by EthanHeilman

>It's entirely doubtful that humanity could be self-sustaining on Mars even in principle, it is certainly not possible with known technologies.

Citation needed.

What's the blocker here?

Energy production on Mars? Why not Solar or Simple Stirling Engines.

Food/Closed ecological systems? Hard, for sure yeah, but even not particularly well funded small ecosystems like Biosphere2 worked for several years.

The biggest issue seems psychological.