I use the FUTO keyboard. The “AI” features that it includes are local-only predictive text and voice-to-text (both are very good, in my experience). It’s not open source, and neither is GrayJay (another FUTO project), which is a yellow flag, at minimum.
At the same time, they do fund open source projects, most notably Immich, which is a fantastic Google Photos alternative. I’m personally okay with using their stuff, and tentatively happy with them as an organization, but I’m keeping a watchful eye on their behavior.
https://briarproject.org/