Google officially have responded to those accusations stating they do not profile users nor collect any data with their keyboard...

Your choice to trust them, I do not trust then for a second.

Have you checked the permissions you are giving to that app?

Now compare to the FOSS keyboard permissions:

Hard to understand how people trust Google tools not to peofile them and sell their profiles for profit, most of their tools, IMO, have way more permissions than the ones needed to provide the service...