Some Linux/Open-Source Letdowns Last For Years
From that list at the end of 2018, the items that were since resolved include:
WireGuard Is Not Yet Mainlined - This was fortunately wrapped up at the start of 2020 with Linux 5.6 merging WireGuard. Since EOY 2018, we've also seen WireGuard support added to the likes of OpenBSD, FreeBSD, Android's next major release, and other distributions. WireGuard adoption continues ascending and most Linux distributions now are packaging its user-space utilities and making it available now that the kernel support is in the mainline tree.
GNOME Wayland Performance Issues - One could argue that there still may be some GNOME Wayland performance shortcomings, but it's a hell of a lot better off now than at the end of 2018. GNOME on Wayland is basically at parity to under the X.Org session as shown by Fedora Workstation continuing to default to it. Canonical's Daniel van Vugt, various Red Hat developers, and others have done a great job at getting the performance-related Wayland issues in order.
Xfce 4.14 Not Released Yet - Xfce 4.14 ended up being released in 2019. Even more exciting was the recent release of Xfce 4.16, which showed the project could manage an annual release cadence with its stable debut last month. Hopefully Xfce 4.18 strikes at the end of 2021 or at least to a better and more predictable cycle than the long and drawn out Xfce 4.14 happenings from a few years ago.
The GNU/Linux Smartphone - It is tough to say whether this is fully addressed yet... The Purism Librem 5 "Evergreen" smartphone is now shipping, but the software stack still is arguably quite incomplete. Exciting a lot of people more recently has been the Pine Smartphone and the various Linux distributions available there. In any case, the GNU/Linux smartphone scene is at least more vibrant and hopeful than at the end of 2018 at least for niche users.
Meanwhile, the items still not addressed -- or fully addressed -- include:
Open-Source NVIDIA / Nouveau - Sadly, not much has improved since EOY 2018 for open-source NVIDIA support... But we are hopeful for something big in 2021. Since 2018 there has been a few more NVIDIA documentation drops, some patches albeit mostly on the Tegra side, and the Nouveau developers continue scraping by with new hardware support often many months after launch and that is partially due to the signed firmware requirements still in place. But as it stands at the start of 2020, the GeForce GTX 900 series and newer on the open-source NVIDIA drivr is basically garbage due to the lack of re-clocking support (in turn held up by signed PMU firmware complications) in order to run the graphics cards at their rated frequencies. Until that is ironed out the recent generations of NVIDIA GPUs perform miserably on Nouveau. There is OpenCL support that Red Hat has been working on but also still no working Vulkan driver yet either.
Linux GPU Driver GUIs - Not a lot has changed here either since the end of 2018... Intel is looking at offering a Linux graphics driver control panel potentially in the next few months at least when I last talked with Lisa about it. So hopeful on that front we could see some modern Intel driver control panel for Linux this year. AMD meanwhile has stated they are basically leaving the Linux GUI control panels up to the desktop vendors (GNOME, KDE, etc) or the community to address them. AMD does expose various tunables and monitoring interfaces via their kernel driver and OpenGL/Vulkan drivers but so far hasn't committed any resources toward a GUI control panel.
Steam Linux Marketshare Is Under 1% - At least as of last month, the Steam Linux marketshare was at 0.9%. Since 2018 with the success of Steam Play / Proton, the Linux gaming marketshare as a percentage of Steam users has been steadily rising... It's possible in 2021 we will see it over the 1.0% market but I am not holding my breath on any significant increases.
X.Org Still Ever Present On Linux Desktops - Fedora Workstation remains the most significant user of a Wayland-powered desktop by default. Hopefully this year we will see Ubuntu 21.04 or 21.10 transition to GNOME on Wayland by default along with others. One of the last remaining major obstacles is the NVIDIA Wayland support often running into troubles with different compositors or XWayland. But NVIDIA is working on DMA-BUF passing and other improvements. Hopefully this year ahead of the likes of Ubuntu 22.04 LTS we see more Wayland by default on the Linux desktop.
GIMP 3.0 - There have been recent development snapshots of GIMP 3.0 released, but this GTK3-based image editing program still hasn't seen this major milestone. This is while GTK 4.0 was just recently released as well. Hopefully in 2021 we finally see GIMP 3.0.0 christened.
Squeezing The Last Bits Of Linux Performance - Most Linux distributions still aren't tuning well for modern CPUs/hardware and Intel's Clear Linux continues to show there is the possibility of squeezing much more out of the out-of-the-box performance than most Linux distributions are pursuing. There still is much more that can be done for enhancing the out-of-the-box performance of Linux software with the likes of more LTO and FMV usage, better catering kernel builds for today's hardware, etc.
No Clear Next-Gen Linux File-System Front-Runner - The Linux file-system scene remains as complex as ever. Fedora Workstation switched to Btrfs by default last year, Red Hat continues pursuing the XFS+LVM-based Stratis Storage solution, and Ubuntu is using EXT4 by default but continuing to invest in building out their OpenZFS-based installation support. Bcachefs has been under development and potentially mainlining this calendar year. Reiser5 was also announced one year ago as an evolutionary step past the out-of-tree Reiser4. There still is no consensus around the best Linux file-system but a mix of Btrfs, XFS, and the proven EXT4 along with plenty of OpenZFS fans and not concerned about the out-of-tree status. F2FS also continues performing well and being advanced by Google for Android devices and more given the great performance on flash storage.