User blog comment:The Skarmy Goat/Everything Wrong With Chinese Plants vs. Zombies 2/@comment-27808363-20171020060142

Technically Fire Peashooter can be considered better than Repeater. She costs less, she can't be frozen in Frostbite Caves (and can thaw nearby frozen plants) and has a Plant Food ability that damages all zombies that are in front of her in her lane.

This was probably done so that players can get a useful plant easily, compared to needing Puzzle Pieces.