Letting go is not the same as giving up. When we let go, we allow life to present itself in its many variations, some pleasant and some not so much.
The suffering of humans is based on believing that we know what should happen. We are attached to outcomes rather than being curious about how life is unfolding. We want what we want and in squeezing life into our preferred outcomes we are on constant watch for anything we can control that will make the desired outcomes occur. The material world and its fame and fortune does not seem to satisfy our hunger. We think around the clock and sometimes cannot sleep because we are thinking. We regretfully think of the past (which we cannot change) and we plan for a raft of outcomes to avoid trouble. Very few of these occur the way we planned they would, whether we are trying to avoid negative outcomes or whether we are seeking positive outcomes.
The hardest discipline is to observe our thinking as a phenomenon and not as the truth. Being curious and admitting we have no idea of what is going to happen violates our intellect. It makes us feel unsafe. We often live in the world of our imagination and wonder why no one lives in that same world. Most of us are living in some version of a virtual existence until something shocking occurs to wake us up. That may be the purpose of shocking events after all.
So, letting go is not the same as giving up. It may be giving up the fantasy that our thoughts are facts or that they give us some control over the future. Letting go allows life to express itself through our experience as we observe in awe and amazement!