Is life on earth over?

In absolute terms, no. We still have 500 million years, objectively quite a while, before the Sun’s transition into a red giant makes life on the surface impossible for all large animal species.

And even then, it is likely that some particular invertebrates, bacteria and extremophilic organisms may still continue to live on or below the surface for another half billion years before the planet is sterilized completely by the sun.

In percentage terms, yes. As far as we know, life began about three and a half billion years ago in its simplest form, and only half a billion years ago started to develop exponentially.

In fact, the birth of fish, reptiles, amphibians, birds and mammals occurred between 600 and 200 million years ago. Therefore, 77% of the time in which life can proliferate on this planet has already elapsed.