It's right there in the settings in KDE, so I imagine it's one of those type settings Gnome deems not worthy of being configurable and you should use it at the speed they deemed is correct.
Unfortunately that's something the compositor has to handle, so unless there's a hidden setting with gsettings somewhere you're out of luck.
You can't configure it but there's patches around where you can hardcode a modifier with very minor side effects.
The thing with Wayland, and things like libinput, is that it wants to give the compositor a lot of power and hopefully enable more things, so there's not one implementation like Xorg that you're just stuck with what it provides. The compositor knows more about what's going on, and the application even more so. So in theory you can have all sorts of inertia curves. But in the meantime we have this silly situation, where you can't even adjust it at all.
I can adjust to some variation in scroll speed. But in some applications it's just too fast to be usable.
I ended up changing my scroll speed settings in firefox to already have that covered.