Why are there moves called “Bite” and “Crunch” when they have very similar attack stats and styles?

Question

Isn’t the move “Crunch” unnecessary to have, as we’ve got the move “Bite”?

Comments

Bite is usually learned at lower levels, and crunch has higher base power.

---

I see, thank you.

---

I see it as crunch is the more powerful version of bite like it is in real life.

Answer 1

Both moves have different purposes.

Bite:
Base 60 power.
Has a 30% chance to flinch the opponent.

Crunch:
Base 80 power.
Has 20% chance to lower the opponents defence stat.

Source for Bite
Source for Crunch