First of all, I would like to say that this is a great introduction to getting started with the gaming experience on Linux and informing users on what to expect, and that the status quo is actually relatively good, depending on what you are looking for, of course. This is actually coming from someone who is a developer and uses Gentoo, but had to help out people who were willing to give Linux a try and started using Ubuntu or other similar distributions that are more suitable for people for who this is their first Linux experience. Also note that for my work, while we do use Ubuntu, we do not use it for gaming, so I cannot comment too much about that exact experience, other than what I have noticed by troubleshooting other people’s experiences in the past.
One of the pain points I have noticed with Ubuntu, or Debian-based distributions in general, is that the offered packages are often behind, which can be rather problematic in providing that good gaming experience depending on the hardware that is being used, as the software to provide that gaming experience (e.g. LLVM, Mesa, WINE, etc.) progresses at a much faster pace than the (LTS) release cycle of Ubuntu, which is why people sometimes recommend using distributions that offer access to bleeding-edge versions of software instead. To give an example, I remember Halo, the Masterchief Collection being pretty much unplayable on AMD GPUs as the offered version of Mesa still relies on the old LLVM shader compiler instead of ACO. Anno 1800 also suffers from this, and probably a lot more games that are heavy on the CPU side and/or do frequent shader compilation.
Of course, there are PPAs available like kisak’s PPA to get a more recent version of Mesa installed, but I feel that this has the problem that newcomers now get the idea that the gaming experience might be much worse than it actually is, that you now have to explain that certain software components they never heard of before is outdated out of the box, and that to fix this they have to go through the process of enabling a number of PPAs and install more recent versions of those software components. For newcomers there should be one-click experience to have the option to get the bleeding edge software required for a good almost out-of-the-box gaming experience that is the status quo, instead of what it was like n months/years ago (when comparing against a bleeding edge distribution), similar to how you can install Nvidia’s proprietary drivers to get a better experience with Nvidia GPUs on Linux (as the Nouveau experience does not reflect the best experience that one could have in terms of gaming). Similarly, this should be true for getting a more recent Linux kernel as well, so they have a better shot at driver support, in the event they have bleeding edge hardware that is currently not supported by Ubuntu (e.g. every time Intel and AMD release a new CPU/GPU).
In general, for newcomers we should look at what the current experience is, what the current experience could be and how to best offer that with a minimal number of steps and without having to explain the entire ecosystem.