Mainly Swiftkey, which I adopted back when it was an independent app. Now that Microsoft own it I don't allow any data sharing with them (I also turn this off in GBoard, though I rarely use that. The fact that Samsung keyboard doesn't have an obvious control for that is a point against it).
I'm wary of Yandex because I doubt that any Russian company can become that big, and they very are big in Russia, without compromising with the regime. That's not some anti-Russian prejudice, I have Russian friends and colleagues, have worked with Russians for many years, and am very much not a nationalist, but it seems to me that Yandex being in a similar line to Google et al means that all of the concerns you might have about data access and use must apply to them too, but with the extra drawback of them having to operate subject to that regime as well.