Not really, we humans killed most big land animals that we found as we expanded our territory, back when we were hunters. This happened in big "islands" like Australia and Madagascar, as well as all the small islands. There, large animals had lived in equilibrium for centuries, and their extinction matches some short time after humans arrived. An exception are the galapago islands, as they were discovered in the 19th century.

You're using the same logic my dad uses to rail against going to Mars. He says there is no worthwhile reason to go there when more pressing matters on earth are in abundance.

Just like you, he is missing the forest for the trees, angrily ignorant to the fact that the knowledge you gained from trying to achieve a seemingly worthless achievement is the actual value, not in the achievement itself.

The achievement is just a convenient goal to make the science more exciting to the general public so as to garner more financial support from both private and government sources. Each of the steps needed to gain that achievement may not have gained as much funding as they do now if they were presented separately from that final goal.