KDE devs have been quietly working on Plasma Keyboard, a new on-screen keyboard for desktop and mobile part of the “We Care About Your Input” KDE Goals initiative. Although not ready for texting yet, it has been making progress. Hopefully it’ll be in a screen near you soon. Join the effort!
https://invent.kde.org/plasma/plasma-keyboard
It’s just a Plasma skin for Qt Virtual Keyboard. Not that this is bad but KDE developers are co-maintainers of Maliit and ended up contributing very little.