There's geological, and then there's ecological. Mars has geology but has no ecosystem discovered thus far.
So the question, "should we replace one ecosystem with another on Mars for our own benefit?" doesn't really make much sense. There isn't anything to replace, as far as we can tell right now.
Perhaps consider instead that creating an ecosystem where there wasn't one before is of an overall net benefit to life in the universe, of which all current evidence points to being present on only one planet.