SovereignCopper
True, OpenBoard is abandoned afaik.
I prefer FlorisBoard as I want my keyboard to have the perfect size. In my 4a it was half of the screen, on the 6a it is a bit less.
The AOSP keyboard really isnt great and that is not a problem. There are HeliBoard, Floriaboard, FUTO Keyboard, Fossify Keyboard, Unexpected Keyboard, KryptEY and probably more cool keyboards