Elrond: based on my understanding of the One Ring, we want a ringbearer who won’t be tempted to use the ring or powerful enough to do anything if they succumbed to it. 

Gandalf: so…like…a baby?

Elrond: exactly what I was thinking. But a baby will turn invisible if it puts the ring on, and no one would be able to find an invisible baby!

Gimli: not if it was a dwarven baby! it wouldn’t turn invisible.

Elrond: perfect! we need a dwarven baby to be our ringbearer.