We are in the peak Linux desktop era and it might be downhill for a while. When I say peak Linux desktop era I mean you can pick up nearly any machine off the shelf, install Fedora, Ubuntu, Mint, Debian or Manjaro as they are and get straight to work without fiddling with the computer itself. There are some corner cases where things are more difficult but even nVidia PRIME works well these days. In my opinion the Linux desktop is basically at parity with the proprietary options in terms of "just works." You can boot the machine up, do the initial create your account and sign into your cloud stuff and boom you're done just like any other desktop OS. The image of Linux being about messing with the computer is really outdated. It's a good productivity tool, as much so as Windows or macOS in my opinion. Yes it's different and takes some adjustment to the new workflow, just as if one were to switch from Windows to Mac or vice-versa, but it's not inherently broken. No you don't have to touch the CLI for anything on the major desktop environments if you don't want to.
A lot of this is due to monumental efforts on the part of volunteers but also companies like Red Hat and Canonical. However there are two major players who have contributed huge amounts of code, time and funding to the Linux ecosystem that people seem to forget about: AMD and Intel. Intel is a major part of the reason why modern USB standards work on Linux and AMD has documented and open sourced their graphics drivers. Intel and AMD pay developers to work on this, upstream code into the kernel and have generally been decent community members. Even with all their flaws we owe them some thanks for Linux hardware support being where it is along with the fleet of volunteers maintaining things at organizations like freedesktop.org.
Late last year Apple released ARM based Macs. Microsoft has just announced a translation layer to allow X64 code to run on ARM on Windows and has shipped ARM machines for years. Many OEMs have been shipping ARM Chromebooks for a while too. The Apple announcement came with their usual showmanship and is going to make the rest of the world take notice. Like everything else Apple does the rest of the industry will be tripping over themselves to follow suite. I wouldn't want to be Intel or AMD right now or be holding their stock. ARM is likely the future for most devices outside of enthusiast desktops or legacy applications. I think that even enthusiast desktop platforms will switch over, but that's just my opinion. Yes I realize Chromebooks are technically Linux as is Android. This is more about the FreeDesktop type of future. Chromebooks and smart phones are still very locked down devices and do not support the full range of what the Linux desktop today can.
This brings us back to peak Linux desktop. Linux runs on armhf and arm64 just fine. The problem is the ARM ecosystem is a mess of cobbled together proprietary things. Even if you aren't dealing with a locked bootloader power management, boot processes, IO and graphics varies tremendously from one ARM platform to the other. Unlike X86 and X64 where UEFI, ACPI and other well documented standards are implemented across nearly the entire range. There are very few ARM vendors working on open sourcing and upstreaming support for their platforms into the Linux kernel either. Even the beloved Raspberry Pi relies on out-of-tree patches for full support. Most of the other consumer facing ARM boards out there for Linux rely on reverse engineering in some part or the other, even if just for the Mali graphics.
There is hope, a standard called ARM ServerReady mandates UEFI and ACPI for compliance. This solves the boot process and power management problem. Despite the data center centric name this standard works fine on desktop and laptops as well. Microsoft's Surface products used ARM ServerReady as does the ARM based Lenovo Yoga. Tyan and Gigabyte have been selling a range of ARM servers that fully support it as well. Indeed you can grab an arm64 Debian installer and slap it right on the Tyan and Gigabyte machines. They work great as long as you don't need graphics.
Alas, this only solves part of the problem though as you're still dealing with a lack of driver support. Mali graphics have a reverse engineered driver that has been mostly accepted into the kernel the last time I checked but like most reverse engineered things it's usable not not fully featured. A very similar feeling to the Nouveau driver for nVidia cards. Most ARM options for Linux on the desktop or mobile right now are low performance patchwork things like this.
What we need is an ARM vendor to step up like Intel and AMD have and work hard on upstreaming support into the Linux kernel for all their hardware and ServerReady to become the default ARM platform. Huawei is probably the closest on this as the Chinese tech sector is ditching western software firms in favor Deepin and Ubuntu Linux. I think a lot of the FUD about Huawei hardware is just US government sabre rattling. I've seen no proof of it and honestly these days it's pick your backdoor if you're using anything from a Five Eyes country anyway. Until someone starts working hard on upstreaming support and ServerReady becomes the defacto standard Linux on ARM is going to be a mess and will revert back to hobbyist only territory for the desktop. I've been using Linux on and off since the late '90s and early '00s. I remember the good-old-bad-old days before Intel and AMD got onboard and I don't want to go back. That's where the "4 hours and 6 kernel recompiles to get your network card to connect" meme came from. I've got other things to get done now and cannot spend that kind of time minding my machine.
Don't get me wrong, I don't think the Linux desktop is going anywhere. But I think the mid-future is more like the Raspberry Pi or PineBook Pro and less like a ThinkPad or XPS with Fedora, Mint or Ubuntu on it. It will be a tool for people to create one off projects on, not the robust desktop we have today. There may be a open, performant, upstreamed and widely available ARM platform for Linux in the future but I think in the meantime were in for a decade of pain. Again, I could be wrong, that happened once before in the 80s.