Too many toys can overwhelm a child, leaving them flustered and unable to focus. They might end up playing with one toy only to discard it, much like a bear breaking sticks—one after another. This results in no toy being fully engaged with, keeping the child stuck in a simple fiddling phase.
In reality, toys primarily serve to support and promote a child's physical and psychological development. It's not about quantity, but suitability. Suitability means two things: first, it must be appropriate for the child's age group; second, it should aid in the child's normal development at that stage. For example, a child around one year old is learning to walk. At this stage, a pull-along duck toy is ideal. It makes sounds that excite the child and helps strengthen their walking skills.
Generally, two or three age-appropriate toys are sufficient for any developmental stage. If you have more toys, categorize and store the others. Only bring out new ones when the child has clearly lost interest in the current toys and shows no fresh excitement.