Can you provide a reliable source to verify it?
It's not nothing, but it's something. And, at least on my phone, it's not obvious if it can be turned off.
https://scholar.google.com/scholar?lr&ie=UTF-8&oe=UTF-8&q=Fe...
FUTO Keyboard is quite nice.
The integration with whisper is nice too.
https://support.microsoft.com/en-us/topic/microsoft-swiftkey...
Always assume companies will gather, use and share your data in all ways they legally can. The burden of proof is never on the user that companies don't milk us. Calling it "misinformation" as someone further above did is bizarre. This is the default business model of big tech.
Facts do matter, and I appreciate those that make an effort to state them correctly.
But to answer the question, Gboard absolutely uses your data. And it's right there in its privacy policy.