installing it successfully is an accomplishment

Not really with archiinstall, but indeed as you say reading the manual is an expectation. Their philosophy is "creating an environment that is straightforward and relatively easy for the user to understand directly, rather than providing polished point-and-click style management tools", as well-summarized by Wikipedia.

wants to shape their OS and user experience as they think is best

tbh that goes for every distro. It's just that Canonical is more hands-on with its approach. The major complaint with Snap besides performance issues is Canonical making it so that only the Snap versions of popular apps (most famously, the bundled Firefox) are available by default.