It's nice that Google is releasing something, but the 3 datasets (https://crowdsource.google.com/about/open-source/) only cover only a fraction of the Crowdsource tasks:
Food compare: Compare the characteristics of two food images.
Response rating: Evaluate the natural-ness of a bot response.
Audio donation: Record your voice to improve speech technology.
Food facts: Tell us if a food dish has particular characteristics.
Food labeller: Tell us what food an image contains.
Semantic similarity: Judge whether two phrases have the same meaning.
Chart understanding: Judge whether charts are understandable and trustworthy.
Glide type: Glide your fingers on the keyboard to type the text that you see.
Audio validation: Listen to a short audio clip and determine if the pronunciation sounds natural in your language.
Image label verification: Tell us if images are tagged correctly.
Image capture: Collect and share photos of your part of the world.
Translation: Translate phrases and words into different languages.
Translation validation: Select which phrases are translated correctly.
Handwriting recognition: Look at handwriting and type the text that you see.
Sentiment evaluation: Decide if a sentence in your language is positive, negative or neutral.
Smart camera (Android Lollipop 5.0+ required): Point at an object and see if the camera can guess what it is.
Even in those 3 datasets, Google does not disclose the proportion/percentage of the crowdsourced contributions that are released publicly. I would not contribute to Crowdsource with the expectation that my contributions would help build a freely licensed dataset.