Is open source experience overrated

The power of working on open source projects for building job prospects is all in networking. You are increasing your luck surface area by expanding your network. The more seeds you plant, the better chance you have of one of those seeds bearing fruit right when you need it.

Your efforts might not help when you are applying for a job which is disconnected from that web which you have built. Expecting that a recruiter or HR person is going to be impressed by open source work you have done is like expecting that your months long study of Spanish will help you better communicate with people on your trip to Japan.

A college degree isn't enough by itself to guarantee you a job and neither is anything else most people could put on a resume or cover letter. Figure out the type of work that you would like to be doing and come up with a strategy for that area. For some areas, open source work just might not be very important. Be adaptable!