I dont think its a big loss to the universe if humans go extinct. Humans didnt engineer the biochemistry of life or produce the atmosphere or the over rated buggy brain.
Even letting aside any survival mechanism we have there are two rational posibilities:
1. We are alone in the universe => super huge loss of complexity and consciousness
2. We are not alone but at Universe scale intelligent life seems rather scarce => still huge loss in diversity
That's why it's important to find joy in the moment and ways to share that joy and happiness with those around you.