If the tigers go extinct, the entire system would collapse.For e.g. when the Dodos went extinct in Mauritius, one species of Acacia tree stopped regenerating completely. So when a species goes extinct, it leaves behind a scar, which affects the entire ecosystem. Another reason why we need to save the tiger is that our forests are water catchment areas.
Therefore, it’s not just about saving a beautiful animal. It is about making sure that we live a little longer as the forests are known to provide ecological services like clean air, water, pollination, temperature regulation etc.