What's needed is a Dropbox analogue for Linux -- something that doesn't do anything that isn't already possible, but that makes things that are possible accessible to non-specialists.
It looked like SteamOS was going to be a contender, but apparently not.
This is impossible by design. Decades ago there were some distributions that had this as a goal (e.g. Mandrake, Suse), they included an application similar to the Windows Control Panel to manage everything. But such applications can never reach into all the corners, unless the distribution is severely locked down. The example of this extreme is... macOS. And still, there are some cases where dropping into the command line is the better or even the only option.
Back on Linuxland, the userbase realized this about two decades ago, when Ubuntu launched. Having a nice default experience was considered better than having easy tweakability, because Ubuntu could also be configured to the fullest extent in the classic Linux way of reaching into the guts of the system and rearranging things to taste. Not that I would ever recommend tweaking Ubuntu too much, but it can be done.
What about the other end? Most people who like fiddling with Linux by reaching into its internals have settled on distributions such as Arch, where this way of managing the system is expected and thus the distribution works to ensure this experience is as easy and predictable as it can be, by providing a good happy path experience for common scenarios, and providing top-notch documentation for common and uncommon customization options, or minority hardware platforms and devices.
The control panel doesn't need to reach all corners.
Just enough corners to cover day-to-day usability so that new users would be able to help themselves if they get stumped.
That set of corners has been pretty much covered by Windows 95 when it comes to the GUI.
For tweakability, command-line interface isn't unfriendly — the commands are.
People love talking to ChatGPT. This tells you how friendly typing interface is.
I'm not saying that natural language processing should necessarily be a feature of the interface (although it could make a lot of things much smoother), but FFS, an interactive dialogue-based CLI is a much friendlier thing than "figure out the right incantation" paradigm.
It looked like SteamOS was going to be a contender, but apparently not.