Even my child has benefitted from it a lot. Don't expect wonders from playschools, but it is a good beginning for the child. It will make him sing and dance together with other kids. That will bring some confidence in the child. And as age progresses, he will learn to talk and emote and express better.
Some children are late starters.
But there is nothing wrong with them. They are just a little slower than others. Therefore, do not worry. And playschool will just give a different environment to the child. That is not a permanant solution.