Atmosphere of Mars

[Trolidan7]

I surfed a day or two ago on the atmosphere of Mars.

While doing so I looked at a phase diagram of water.

There is dry ice, or frozen carbon dioxide near to
the poles of Mars, but wondered whether at the
atmospheric pressure of Mars, water sublimated
or not.

I found that the freezing point of water did not
go down in temperature much when you reduced pressure
from 1 atm to .007 atm, but the triple point, where
the temperature of boiling and freezing meet to be the
same, is at near to the atmospheric pressure on Mars.

I wondered, is this a coincidence?

Could there be some interaction between frozen carbon
dioxide, and frozen water, that keeps the atmospheric
pressure near the triple point of water, as an interaction
between frozen carbon dioxide and frozen water? Could
this even allow water-carbon dioxide composites to flow
like glaciers on Mars? Or is there really close to no
interaction between the two, the triple point of water
with respect to pressure is simply a coincidence?