Organic molecules simply will be broken down rapidly near the surface.

I am not saying I do not believe life of some sort is not possible, in fact I think there is a 'high' possibility that life existed on/in mars sometime in the past, and IF it did, then I think its a near certainty that it exists now... but FAR below the surface... mere meters will not be sufficient.

I am thinking of the life we find trapped in groundwater kilometers under the surface of the Earth...

And the Mars sample return was cancelled - along with most of the other things NASA was attempting to do...

We will find water near the surface- mostly frozen, but the surface conditions - as we understand them- are not compatible with life of a type we are likely able to detect, nor its chemical remains.

We might find billions year old fossils, and we should keep an eye out for that, but extant life or its organic chemical remains? No- not anywhere we are likely to reach anytime soon.