Yeah, the ARM situation is pretty impressive now-a-days.

Again, I mostly know about Raspberry Pis (RPi 4's specifically) and those are mostly pretty low-power/low-CPU-speed kind of devices. And so there are some limitations with regard to just how much "oomph" the Raspberry Pi has. Not because it's an ARM device rather than an AMD64 device so much as because it's really cheap (which is both a feature and a bug) and low-power. For example, last time I tried using Chromium, I found it nearly unusable for how slow it ran, but Firefox works great. (Though I do turn off things like smooth scrolling animations and such just to lower how much CPU it uses. It's still "regular Firefox", though. Not some "minimal" fork like Fennec or anything.) But again, that's mostly because the Raspberry Pi is low power, not because it's ARM. But the Raspberry Pi also has good 3d graphics support, so Luanti runs surprisingly well and very playably. I'm also kindof a terminal-or-die kind of guy, so not using heavy GUI apps isn't much of a problem for me.

But as to the issues that are specific to the fact it's ARM rather than AMD64, there are very few now-a-days. Binaries, for instance aren't portable between ARM and AMD64, of course. Very few application just straight up don't even run on ARM. (Cura is the only one that comes to mind, and it's been a long time since I tried it, so that might have changed by now. Cura's kindof a terrible piece of software, though. Good slicer, but the way they just don't have any interest in making it cleanly/easily runnable on various systems makes it a huge pain to the point that some Linux distros (Gentoo, for instance) have given up supporting it even on AMD64.) I've never tried to run Wine on a Raspberry Pi, but it looks like there are options for doing so, and running x86 and AMD64 applications on it. But basically every feature of your browser (including streaming video and WebGL and stuff) works as expected (again, depending on how powerful your ARM device is). Aside from problems with Arch Linux Arm, whatever distro you settle on will have great support for the apps you're used to using on AMD64. And you'll have your choice of DE/WM the same as you do on AMD64. Etc.

Oh, I guess one more caveat I'll mention. Some of the Raspberry Pi's RPi-specific hardware tends to change a lot over time. The drivers update and there are new ways of doing things that don't work quite the way they used to. The main places I've seen that happen are in the audio drivers (after one update, the audio didn't work and I had to go down a bit of a rabbit hole to get that working again), the graphics drivers (a few years ago, they released FOSS graphics drivers for the RPi and that changed some of the options available and such, and the main symptom I've seen of that is that documentation may be out-of-date and apply only to the old way the graphics drivers work, so it's definitely worth making sure you know roughly when changes have taken place and that you're looking at documentation that applies to the latest), some of the miscellaneous boot parameters (on Raspberry Pis, there's a /boot/firmware/config.txt file that has a bunch of boot-level kernel options), and GPIO pin access.

Which leads me to something else I didn't think of until just now. The bootloader, driver options, kernel options, and the installation process tend to work differently for ARM devices. With AMD64, you kindof expect UEFI (possibly with legacy BIOS support) to be the norm. With ARM that's rarely if ever the case. I don't know that secure boot is likely to be available for very may ARM devices. Disk encryption isn't something I've gone to the trouble to figure out how you'd do. You don't use Grub, you use U-Boot, or in cases like the Raspberry Pi, the bootloader is kindof hidden away from you except that as you install it and configure it, the kernel/config/driver files go in the right place on the SD card to make sure the bootloader can find them. And the installation process tends to be "stick an SD card into another computer, DD this disk image onto it, and stick it into the target ARM device". Depending which distro you're using, from there it might take you into an interactive installer kind of thing (like with Raspian) or it may be more low-level (like with Arch.) And if you follow the default installation instructions for your distro, you most likely end up with a little less control over things like the partition layout, whether you're using LVM or BTRFS, etc. If you wanted root- or home-partition encryption, my guess is you might have to take an existing installation disk image, dissect it, and build a custom disk image with certain partitions encrypted out of the result before DD'ing it to the SD card. (Ok, I took a break here to check and see if there are guides on how to do full disk encryption on a Raspberry Pi and there are.)

(Side note. You may have to decide when installing a distro on an ARM machine whether you want the 32-bit ARM distro or the 64-bit ARM distro. If you want to run on an older ARM device that doesn't support 64-bit ARM, you'll have to go with the 32-bit ARM distro. If you want to run x86 Windows apps on Wine, it's definitely recommended to use the 32-bit ARM distro. Otherwise, 64-bit is the way to go.)

Ok. Jeez. This ended up being a long post. That's about all I can think to say at the moment.