Wikimedia Foundation is paying off, it is not the financials that are to be studied. For the WMF to be more successful, it has to increase its reach and bring more information to more people.
As more people are moving towards "mobile" devices, it is important to be credible on all devices that are categorised as mobile. That takes different technology and all new technology needs to be implemented without disrupting the main business.
The numbers look great; 74% growth YoY. This includes the wonderful growth due to Wikipedia Zero, it is obvious that the quality needed to support mobile devices is increasingly relevant.
There are many components to MediaWiki being developed and there must be a roadmap to bring much of it together. It does include everything from making sure that content in all the languages can be read on a mobile to adding and editing content.
What makes the achievement of this roadmap so hard are all these little DIY projects that paid off so well for its users. They hate to lose their tools. As technology shifts, they invariably will suffer. The main goal however is to get more people to use, interact, edit with all the Wikimedia content. It is hard work, a struggle and it is continually a work in progress.