Parents shop by the stage their child is at, not by the kind of toy. Pick a stage and you will only see what fits it.
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Babies, grasping, rattling, first textures
Everything goes to the mouth, and a toy is judged on how it feels.
At this stage a toy does not need to do anything clever. It needs to be the right weight, the right size for one small hand, and able to survive being chewed, dropped and washed.