Oh boy looks like my weekend will be spend learning and trying to install Arch without a graphical installer. To be fair Manjaro on my laptop was my first try at Arch. I never thought how much I will come to like AUR.
EndevaourOS is already on my gaming rig so plain Arch for my laptop seems like a good challenge. Farewell Manjaro, I learned a lot
Going to second other comments. Even without archinstall. It feels like it will be harder than it is. Umm, just save yourself a bit of time and configure the network and install a console editor (nano/vim whatever) while in the chroot (if going full manual). It was a minor pain to work around that for me.
There are pages discussing how to do everything (helps to have a laptop with browser, or a phone to look them up). At the end, you generally know exactly what you installed (OK no-one watches all the dependencies), and I've found any borks that happen easy to fix because I know what I installed.
It's not that hard, just read the install guides and instructions. My first Arch install was like 8y ago and I expected it to be difficult - it wasn't.
After you figure out how to properly partition your disk, you learn how the entire setup is actually quite simple
Basically, Mount partitions, pacstrap to install the base system, generate fstab, chroot in, create a unprivileged user and add it to sudo, setup grub, configure internet, exit chroot and unmount, reboot into the newly installed system, configure X11/Wayland to your liking
Installing Arch is a lot easier than fixing a bad Manjaro update. I get that it's intimidating, but it's really quite easy if you can follow instructions, but budget a couple hours your first time because you'll probably second-guess everything. The second time should be more like 30 min.
'Till you figure out that, on Arch, if you missed/broke anything, you can boot into the Arch USB, mount your root into /mnt, and arch-chroot in to fix whatever is broken
Yup, a live image works in a pinch. IMO, just use BTRFS on root and install something like snapper to handle snapshots and you shouldn't need the live USB (unless you bork your bootloader somehow).
I highly recommend BTRFS as your root filesystem, and then configure snapshots. This way if an update goes sideways (pretty rare), you can roll back and wait for fixes.
I haven't used Arch for a few years, but my openSUSE Tumbleweed install came with it by default, and it has saved me a few times in the 7 or so years I've used it. Maybe the new instructions include that, idk, but you'll be glad you have it.