“... [After 1 e4 e5 2 Nf3 Nc6 3 Bc4] I recommend 3...Bc5 instead of 3...Nf6 to young players who have just started to learn chess openings. However, the Two Knights Defence is a sound opening, with many exciting lines, and it becomes a good choice once you have gained more experience in chess. ...” - GM John Emms (2018)
Giuoco Piano is better than Two Knight Defense explained

Bc5 makes White have to play c3, which is passive blocking the knight and not helping a piece get into the game. But it prepares to thrust d4, so it's the most ambitious try for White. Nf6 on the other hand, justifies the more passive d3 to defend e4. It is no longer considered as passive when it is justified.
Except that nowadays grandmasters generally play d2-d3 in both lines.
better than the Two Knights Defense*
Bc5 makes White have to play c3, which is passive blocking the knight and not helping a piece get into the game. But it prepares to thrust d4, so it's the most ambitious try for White. Nf6 on the other hand, justifies the more passive d3 to defend e4. It is no longer considered as passive when it is justified.