We notice viruses and cancer because they are anomalous.

Philosophically speaking, us creating pollution is bad vs a tree creating oxygen because we are killing species at a rate 1000x the background rate. That's objectively bad, extremely fucking bad.

Any philosophy that doesn't recognize mass destruction of life for the sake of temporary individual profit as bad and not normal is _severely_ deficient, to the point of being utterly useless or even harmful.

Your argument is not robust at all. Everything we notice is an anomaly? We don't notice viruses and cancer because they are anomalous to nature. We notice them because we are observers of existence.