It’s been there for a long time. 🙃 I think some distros come by default with maliit keyboard, you just need to enable it, or install then enable. Personally I am using corekeyboard, it’s the only one with modifier keys (somehow neither gnome nor kde default ones even allow to modifiers).
Osk situation is terrible in general, true, with wayland migration it became even worse. But for basics default keyboards for gnome and kde work.