Can you define groundbreaking? In a proper historical context, one might say the same about the likes of Newton, Euler etc. Mathematical ideas don't just happen

Can you define groundbreaking? In a proper historical context, one might say the same about the likes of Newton, Euler etc. Mathematical ideas don't just happen out of nowhere. Everyone is inspired by something that was done before. So truly groundbreaking things are mostly a myth. The closest it gets is when someone takes ideas from one field and unexpectedly applied it to solve ab important problem in another field. Like Poincare's work on three body problem and celestial mechanics.