There is only one feature you will find with free software that isn't present with proprietary alternatives: The possibility of reading, altering and redistributing the source code. The biggest "sell" for these open features is audit-able security. If your boss sees no value in those possibilities, you're screwed I'm afraid.

In terms of general features there is nothing that free software can provide that closed software cannot.
In the same way - a dictatorship can function (superficially) in exactly the same way as a democracy. Trains run on time, children go to school etc. The only thing missing is freedom. To some people freedom holds no value, when the superficiality of an apparently functioning society is in place.