Isn't that the entire point of open source? I need a project, but it lacks the one feature I need. So I build the feature, contribute it back, and everyone wins

Isn't that the entire point of open source? I need a project, but it lacks the one feature I need. So I build the feature, contribute it back, and everyone wins. Is Google supposed to work on Amazon's needs and vice versa for them to be considered good patrons?