Is Architect a “page builder”?
No. Architect is primarily a “content layout builder”. You then add those layouts to your page with one of the methods listed above. In developer speak, Architect replaces “the WP loop”.
Page builders are awesome. But can still be limited. Architect is your content layouts, almost any way you want. That way might be widgets, shortcodes, action hooks, template tags, Blox blocks, Beaver blocks.
So, essentially, Architect lets you build custom blocks for builders like Beaver and Elementor.
Any page builders that support shortcodes and/or widgets can be used to display Architect layouts. And a Beaver Builder (aff) module is included.
This document can be viewed online at: https://architect4wp.com/pz_snippets/is-architect-a-page-builder/