A lot has changed since io.js and Node.js merged under the Node.js Foundation. The most impressive change, and probably the change that is most relevant to the rest of the community and to open source in general, is the growth in contributors and committers to the project.
A few years ago, Node.js had just a few committers (contributors with write access to the repository in order to merge code and triage bugs). The maintenance overhead for the few committers on Node.js Core was overwhelming and the project began to see a decline in both committers and outside contribution. This resulted in a corresponding decline in releases.