I think the main issue is too much fragmentation within Linux. There's the whole choosing the distro, choosing a desktop environment (or window manager), figuring out how to use the packages for your distro, etc. Then you have issues like some software being too outdated for your distro or not packaged at all so you look into Flatpak but it's a whole other system on your computer to have to keep track of and maintain or the software you need is not there either so you have to compile from source. There also comes the issue of getting help when something breaks. There's hundreds of different little bits in every single distro that makes it a pain in the ass to fix sometimes unless you're using one of the few large distros where the guides actually work.

I really don't think Linux will become truly mainstream for the every day user until there is a proper "default" experience like what Windows and MacOS provide. Sure some people will say use this distro and this desktop environment and it'd just work but that forces the common person to trust the other person online and that common person has to make a choice. If their first experience on Linux is bad, they'll just throw it off altogether and go back to Windows or MacOS. Everyone has a different first experience with Linux.

I'm not saying strip Linux of all configurability. I'm saying there needs to be a focus on a standard Linux distro with a standardized desktop environment and standardized overall user experience. If the user wants to change any of it, they're free to do so like anyone can with Linux right now. Also, the user should be able to manage the system entirely through a simple GUI. If the user has to for any reason go into a terminal, Linux has failed at being usable by the common person.

I say this as a person who uses Arch (btw) on my laptops and desktop and Debian 12 and Proxmox 8 for my servers and RHEL 8 at work. I really love Linux but I just can't in good faith recommend it to a person who wants to just use their damn computer unless they're willing to put up with the massive fragmentation and lack of support in the community.

Tl;dr Linux doesn't have a "default" experience like Windows or MacOS so a common user will struggle to even get started or look for help/advice