tl;dr: "With the Ryzen 5 2400G, AMD has completely shut down the sub-$100 graphics card market. As a choice for gamers on a budget, those building systems in the region of $500, it becomes the processor to pick."
Well, almost. Integrated graphics generally take the place of additional CPU cores. For example, there is no 8-core Ryzen with integrated graphics. So if you need cores (like for compiling code) then you end up with a discrete graphics card even if you don't need fast graphics.
I actually wish Intel would make a cheap discrete graphics card for that purpose, because they have the most stable Linux graphics drivers.
So I install 16.04, the most recent LTS release available because I don't want these machines to turn into a pumpkin after less than 9 months but the graphics are a total fail. SVGA 800x600 only.
So the kernel on that release is too old and updating the kernel on Ubuntu is fraught with peril. So I look into third party drivers and find that their support was dropped entirely from even the third party Ubuntu support. So I go to ATI/AMD's website and find the driver package, but it turns out to be a tarball full of .debs with zero instructions on how to install or enable them. I was having flashbacks to working on Linux installs in the late 90s and having to hack everything to get it working.
In the end I had to install 17.10 and apply the hacks to make it work[1] just to get the graphics running, and now I'm going to have to revisit those machines in a couple of months to upgrade them to 18.04.
[1] Disabling the new systemd DNS resolver that crashes on literally every lookup attempt on our network. Also had to learn how to program the modeline equivalent for Weyland for when you're going through a KVM and don't have EDID. This was no picnic in later versions of X, but I had already figured it out and had earlier versions as reference. I still miss xconfig sometimes.
It's gonna be a breeze in a few month though. And once that happens, the open source AMD drivers are going to be stabler than the Nvidia blob again.
You should have read the friendly documentation! I have AMDGPU running on 16.04 after running an install shell script (amdgpu-pro-install) in the tarball, as spelt out by the docs.