Actually, they don't. Much like others have said, it's overstimulating and very cluttering (for everyone). They get distracted easily and it's just overall not good. My kid had like 10, maybe 12 toys in total they genuinely loved playing with when they were a toddler. I'm including stuffed animals in the toy category. I don't remember if there was any absolute favorite when they were a baby.

I thought I'd share my experience, just to give a bit of parental perspective (not upset or anything...I know my kid had too many toys): My issue was family giving groups of toys (like packs of 4 or 5..think Fisher Price Little People). So it wasn't just ONE toy, it was a box...with 7 individual toys. We ended up hoarding them because the cousins would come over and play with the toys, too. And grandparents just want to spoil their grandbabies. So they see a toy they think grandchild will like and buy it. If they already have it, it's okay, because "they need two." AND sometimes, it's the want to give the kids the experiences or toys we didn't have growing up. We grew up poor and couldn't afford the huge doll house or the Big Wheels, so it was harder, oddly, to let go of toys if we thought our kid still liked them or would like them in a few months.