In a most informative article, David. F. Coppedge contrasts known facts as to why Mars might be lifeless with science writing that relentlessly attempts to paint it as hopeful. Just two examples:
(3) Mars has no global magnetic field to protect life. (4) Mars has no ozone layer to protect it from UV radiation.
David F. Coppedge, “Evolutionists Find it Hard to Imagine a Lifeless Mars” at Creation-Evolution Headlines
vs.
Mars rocks collected by Perseverance boost case for ancient life (Phys.org). The only evidence offered in this simplistic article is that certain rocks in the Jezero Crater where the rover Perseverance is operating could have had contact with water in the past. “If these rocks experienced water for long periods of time, there may be habitable niches within these rocks that could have supported ancient microbial life,” said one female NASA geologist suffering from hydrobioscopy.
Earthly rocks point way to water hidden on Mars (Penn State News). Water is a necessary but not sufficient condition for life on Mars. Mars has an abundance of an iron mineral called hematite. A Penn State doctoral student found evidence to support a “once-debunked 19th-century identification” that some forms of this mineral could contain water. The possibility of Mars having hydro-hematite was enough to switch on this student’s hydrobioscopy buzzer.
David F. Coppedge, “Evolutionists Find it Hard to Imagine a Lifeless Mars” at Creation-Evolution Headlines
People don’t want to be alone or to believe that they are alone. That, far more than any evidence, drives the demand for life on Mars.
Of course, there could be life there but that’s not why people believe it.