I use the pre-built drivers in kernel. No need to worry or anything, just plug-and-play.

You don't want amdgpu-pro unless you're doing something really specific that needs OpenGL and OpenCL. amdgpu built-in is good enough for most games and use cases.

Mesa is just a graphic library. You'll need it.

Edit:

amdgpu-pro may be even worse to gaming then the amdgpu built-in.

AMD just doesn't have any official gui setting software on Linux
third party tools like CoreCtrl will help you with some settings like overclocking, undervolting, etc. and for basic settings your desktop environment of choice already give you control over resolution/framerate/gamma/whatever
for an ingame overlay and fps limiting take a look at mangohud

there is also a lot of confusion because there are different software names for kernel driver (i.e. amdgpu) and userspace driver (i.e. Mesa) with additional varieties on top like vulkan-radeon and amdvlk (which is included in amdgpu-pro and typically worse)
luckily most people don't really need to care about that since most linux distro already give you the best gaming choice out of the box and updating your system will also update your amd driver

For gaming, it works out of the box. You don’t need to install additional drivers. The other drivers are only necessary when dealing with things like machine learning and AI. They don’t offer better gaming performance and will only introduce problems similar to Nvidia.

Yep, it just works out of the box, that's how nice the drivers are! You get updates to them as part of your Kubuntu updates, although there's a PPA to install newer Mesa if you really want to. But for the most part, unless you need specific features of newer versions like for a new game release or a just released GPU, you can use the one that you already have just fine.

There's no control panel because it all uses generic interfaces that also works for Intel and all other open-source drivers. For example, monitor configuration is configured from your DE's display settings. You do need a third party GUI for overclocking.

If using Wayland, things like variable refresh rate is enabled by default and works out of the box. When HDR is ready, that will be turned on by default too most likely.

People already said that you are good to go with the built-in amdgpu kernel driver. I only want to add, that you have made a great choice; I am running with the same AMD 6700 XT gpu and it just rocks with wayland and has no issues when resuming from hibernate.

The last more demanding game I played was Elite Dangerous (max settings, except anti-aliasing) with 60 FPS capped (my monitor cannot do more) on 1980x1200 resolution. It was a pleasent experience without crashes related to the graphics driver. (:

Edit: And mesa updates are always exciting. They sometimes improve overall performance and stability.

How is it going? I also run Kubuntu and I'm waiting for Black Friday to buy that same card.