Looking for playdates for my baby seems impossible

Looks like every time I respond to someone posting about meetups or get together, im getting ignored. Bottom line is, Its so frustrating trying to meet people w babies to do a playdate with. I'm in san francisco and down to meet at park, zoo, beach or wherever that's baby friendly. I am in my 30s and would love to meet others with their spouse and babies. Anyone else in same boat?