Imho /e/OS is quite sophisticated, so maybe not the best candidate for a minimalist environment. I guess it was in order to learn about Android that I wrote this My wish list for /e/ - #90 by aibd, you should be able to follow contemporary links from there (for instance https://gitlab.e.foundation/e/backlog/-/issues/3969).
From your OP you might follow through the work referenced here BoringPhone and Boring Phone OS - #7 by andrelam
For my own part I tried Experimental Custom build 'extra_minimal_apps' for Oneplus One - bacon which is still seen here [CUSTOM BUILD] Oneplus One - bacon Android 11 v1.13-r CUSTOM_SLIM with No Advanced Privacy. These posts try to provide links to indicate the method used.