In some religions an emphasis on tradition and history can seamlessly integrate with that inner quest. These are religions that have continuity. "Follow the Footsteps" only works when you have an unbroken lineage of teachers passing down what earlier masters learned. Otherwise it's just relics.
The question to ask is not whetherCeltic religion (and other lost traditions) can be resurrected in some new-but-faithful form. The question that increasingly demands my attention is, what's the value?
Why spend a life rebuilding lost chariots, when you could already be riding horses?
These questions are part of why the Heroic Life, not Celtic polytheism, is my religion. I know the answers the Heroic Life gives. Respect the gods but don't count on their help. It's polite to honor the local (or ancestral) gods in the manner of the local (ancestral) culture. But this is secondary to the personal quest. Set out in the world to do the things of legend. This is what legend is for. To do is better than to remember.
But how does Paganism answer these questions? The dragon of karma has eaten the world where druids (etc.) made their home. A new world is birthed before us. Is Paganism's focus on dead cultures an anchor holding it down?