Until your average PC user can navigate Linux without issue, Linux will always drag behind Windows. I have said this time and time again. Linux is too fragmented to reliably handle most PC users. The reason MacOS does well is because a user can navigate it with relative ease.
Arch Linux, Bazzite, CachyOS, and all of the other Linux distributions suffer because Linux isn't universal. Want to get an app? Time to figure out how exactly to do that because there are different apps and "app stores" for different versions of Linux. Different desktops, different conventions, different settings panels, different theming that breaks in different ways. A user learns muscle memory in one place and it does not transfer. Right click here does one thing, right click there does another. Settings live under three different menus depending on the OS.
Package managers are another wall. You've got apt, dnf, pacman, zypper, then Flatpak, Snap, AppImage. Then distro repos versus third-party repos versus vendor scripts. This is too much for a new user to try to navigate without making it a serious time commitment. If the path to install an app depends on a flowchart, the OS is not ready for the average person. Software availability is also a major factor. Missing Adobe is not a small thing. Not being able to easily use Microsoft apps, especially for people like myself who HAVE to use them for work, makes it a no-go. You can argue alternatives, but the industry standards are the industry standards.
The Steam Deck works because Valve hid the fragmentation. One store. One runtime. One set of defaults. One recovery path. That is the model that helps non-technical users. Sure, people can go to the desktop and do more than that. But the Steam Deck, much like traditional game consoles, benefits from the simplicity of "install the game and go". That's what the average user wants. The more the experience looks like that, the less Linux feels like a chore.
This is why I want Valve to seriously work on SteamOS to make it an actual OS that can be reliably used by the masses, not just by people who are fine with learning command-line and all the different ways that Linux operates. I hate to say, "Be like Apple," since I think Apple is a sucky company, but I want Valve to be like Apple was with the start of MacOS. Understand what people need from the OS, and work towards making it something that can accommodate the end-user rather than telling the end-user to change in order to accommodate the OS.