I use Gboard and have been meaning to find an alternative, so this is a useful thread though it seems the concensus is there aren't really any.

What I'd love to do is completely remove any reference to stickers and gifs from the emojis selection but it's not possible. The emojis button can be removed from the keyboard, maybe it's time to go back to traditional ASCII.

There was a cool multiswipe keyboard called KeyMon like ten years ago. It was great to be able to dual swipe to type. It brought back memories of t9 typing. Unfortunately, the app hasn't been updated and has been lost to outdated time.

I've been using SwiftKey for about as long as you have and for a while, about once or twice a year, I'd do exactly what you're doing- looking around for a better, privacy focused keyboard. I find one or two and try them out for a while but always end up back on SwiftKey because the predictions are unmatched.

Any of these allow you to change the size of individual keys like Smasung Keyboard?

Seconded, I currently use unexpected keyboard but I really want something with swipe typing.