> why didn’t Google
Because hubris.
One glaring flaw of well-capitalized large tech (perhaps the only one) is thinking they can build something better internally, when they have enough cash to simply buy best of breed off the market.
At times Google understood this: Android 2005, YouTube 2006, Writely/GoogleDocs 2006, DoubleClick 2007, Motorola Mobility 2012, Waze 2013, DeepMind 2014