I only just came across this article from October last year,
Google’s product strategy: Make two of everything | Ars Technica
If true it explains to me a lot about what the heck Google does with having for instance both Android and Chrome OS.
It says Google actively tries to develop competing products in an A/B strategy like when analyzing the impact of different ads, and this is its way of not falling into the trap of becoming obsolete - it has a version of the new disruptive product because of internal competition!