Easy if you go step by step and don’t accidentally skip anything. Archinstall will get you to the same result with lower risk of failure, in a tenth of the amount of time spent. And unless you install operating systems for a living, it doesn’t matter how you get there. Source: Installed Arch on about a dozen different devices, twice without Archinstall.
If you’re looking to learn something, do Linux from Scratch instead. The process is way more granular, way more documented, and way more educational than parroting the steps of installing Arch from the wiki.