I'd say its probably, among other thigs, hardware compatibility issues.

Running Linux on a mashine, most notably portable, that is somewhat recent and is not specifically built with linux in mind is, imo, almost certainly going to cause some, for the average user unfixable, issues. Things like wifi, bluetooth, audio, etc. not working due to missing or broken drivers.

The best way to fix that would be official Linux support by the OEMs, which realistically is never going to happen. Or extremely time consuming reverse-engineered community drivers.

Ok, so I have an ASUS Zephyrus M16 with a Core i19 12th Gen and an rtx 3070. I was able to install fedora and able to get it mostly 100% working, but my two biggest issues where I could not play Destiny 2 (because they didn't want to support Linux and actually would ban players who tried), and the switch between egpu and the discrete gpu that you have to reboot for the changes to take effect. Every once in a while the display wouldn't work and I had to reboot multiple times before it would start to work again because of the aforementioned issues with the gpu. All in all I love Linux but I can't spend any time troubleshooting and just need a laptop that just works.

Fragmentation, there is so many WM, DE, Distros, package managers. This is the beauty of open source but it is also the plague.

Toxic communities, where people are thrashing you if you don't understand sometimes the overly complicated wiki and you dare open a thread in one of the forums to seek for help.

Driver support, sometimes installing your OS requires a lot of manual configuration to make everything work ok your machine the way you want it.

The number one issue for me was games.

Like seriously, why do most developers not give a damn about their Linux playerbase?

Intimidating to install and then an unfamiliar interface and applications.

It might be more accepted if it came preinstalled and simply had a browser like Chrome and an app store, where all the other 'helpful' but confusing apps like Libre office were kept out of the way.

I install it for my family and it would only be accepted if it looked and worked just like Windows or MacOS. All they really need is a browser to get to GSuite or Office365.

Funding. Nobody has figured out how to fund development for large open source OSes outside of the enterprise realm. You crack that, you can have linux be installed by default on Desktop/Laptop computers, and patches that come as a result of that funding benefit the rest of the ecosystem as well. People will use the default, they will complain about it, just like they complain about Windows Update randomly restarting their computer, but they'll use it.

But also the share of people who own laptops or desktops continues to dwindle. Many people don't have and see no need for a computer. So they run Android, which is Linux, so I guess we're winning there?

Whenever I try to go full Linux, 80% of the time I revert back to Windows due to lack of compatibility with games. The other 20% Is due to something breaking or being a pain in the ass to get working. Need to install a program? Here is a .deb file that you have to right click, allow execution. Then you go to execute it and it opens in a text document that has a run button that ends up taking 2 hours to load and ends up failing. Turns out you could go to terminal, CD to the file location and it seems to install.

But wait! 10 dependencies are missing.

I mean... Is Linux even a challenge to anyone that just needs basic stuff? (Ubuntu, fedora, etc)

I only have trouble trying to install shit that's not in repos.

Exiting Vi/Vim 😂

I'm a new user. How do I disable being prompted for a password every time I want change/install anything? I just want password requirement at logon and not when logged on.

Unwarranted fear.

There is a perception of Linux as this hacker, terminal-only OS with a million equal choices and no direction or guides. This is not a true view or at least this is hyperbolic/based on Linux from 15 years ago. It is a stigma that Linux has. Every distro these days has to market itself as "We're the out-of-the-box distro" which is just silly. Out-of-the-box is meaningless. Even Windows users modify their OS in certain ways. However, it breaks the stigma.

Linux adoption just needs more time. Most of the big issues for adoption have been solved in the past few years, and Linux is ready and knowledge of Linux and removal of the stigma is growing.

Nvidia. Within two weeks, their shitty drivers broke my system twice. If I didn't already know about that beforehand, I would've probably quit linux for good after that experience.

The main challenge is resisting the urge to install Linux on your own. Because you will need help at some point, so start now by asking for help.

And then, when you don't find the solution by yourself don't waste time and ask for help.

In time you will get it enough to know what you're doing.

IMO one of the main problems is eliminating the workflow of older commercial operating systems and having to build a new habit of using a new system. There are various Linux-based distributions that manage to give the user everything they need without having to resort to using the specific terminal.

Creating a new habit after spending years developing one for an old system, for me, is the main problem that leads many users to leave it.