If he had lived, the Orthodox Serbs would still feel the heat from the German-Austrian empire. They would have plead to Orthodox Mother Russia for protection, Russia would have mobilized and Germany would have declared war on Russia.
The war would still have been on.
Good point; even an unsuccessful assassination attempt by Princip - let’s say he only lightly wounded the Archduke - would still have the Austro-Hungarian Empire breathing down the neck of the Serbs, who in turn would’ve appealed to Russia for help; Austro-Hungary mobilizes, then Russia, then Germany, and we have still the exact same scenario.
At that unfortunate point in history, probably ANYTHING would have served as pretext for war. Hell, say the Archduke eats some bad goulash and gets Montezuma’s Revenge or food poisoning; the Austro-Hungarians then maintain it was attempted assassination by arsenic or something and the same scenario unfolds.