Like all things: the extremes are never good, and it's all about getting a healthy balance.

- Kids need lots of time with their parents

- Kids need lots of time around other kids

You can do that by sending them to daycare, and ALSO spending lots of time with them when they're home.

You can also do that by taking time off work, and then taking your kid(s) to places with other kids.

Both work; and it depends on your context which works for you.