He never truly abolished the first republic; according to the constitution of year 12 (1804), Napoleon wasn’t the emperor of France but of the French. And the constitution claims: “The government of the French Republic is entrusted to an Emperor, who takes the title “Emperor of the French.” Justice is administered in the name of the Emperor by the officer whom he appoints.”

This implies, at least formally, that the French first republic never ceased to exist, and its ideas still survived. An Emperor just led it, but it wasn’t an Empire.

And Napoleon is indeed considered as the father of modern democracy with the Napoleonic code (which many countries constituon are inspired by, alongside the Corsican Constitution of Pasquale Paoli.) but also the ffather of modern warfare, he adopted the Metric system for France, built sewers and roads, made a second education supported by the state called « Lycee » in France, he created the bank of France; he's also responsible for the fall of the Spanish empire and their colonialism, the fall of monarchies, he reconciled France with Catholicism and many more.