Honestly, why would you ever want to breed canaries! :nono:
Its just a big yellow disaster.

Feathers coating every inch of your house! And the babies moult successively, so the feathers will never stop coming.
Never.
And then, all the food they eat goes somewhere, right? You'll probably be cleaning cages for 25 hours a day--one extra hour into the next day because it takes so long. You may get sleep-deprived and fall asleep randomly to the sound of chirping canaries and their hungry children.
You'll go to work and someone will say: "Hey, what's that?" and pull a yellow canary feather out of your ear or something!
Second, all the noise! Imagine hungry chirping babies! They're naked and needy and if the mom decides they're too much work, then who will care for the little ones? :S
You'll have to run around getting formula to the correct temperature, or keeping the house at a constant temperature, and of course, buying new things would certainly drain you.
Then you'll probably loose your house "because that 38 karat gold birdbath was just
so cute" and you'll be out on the street with a cage full of hungry, noisy, feathery birds who probably just want food.
You look in your pocket.
Oh, a 10$ bill! Enough for a meal.
Then you look at the canaries, and, wait, they need food too.

So you go to the pet store and buy a bag of canary food, and then you don't have anything to eat, so you try a few pellets. Eventually, after eating so much canary food, you start sprouting feathers, and people call you "that canary person" and you'll probably have to move to a forest where you can live with your flock.
The end.

Moral of the story: No, you don't need to breed them, or you will literally be consumed by them and eventually turn into a canary.
Okay, maybe not, but still. Do you really need this? No.
No you don't.
