It is never necessary to use Create Spatial Type on a properly configured enterprise geodatabase.
Create Spatial Type is a limited subset of Enable Enterprise Geodatabase, where only the SDE.ST_GEOMETRY datatype is wanted. Quoting the documentation (emphasis mine):
This allows you to use the ST_Geometry SQL type to store geometries
in a database that does not contain a geodatabase
Your "benefit" is an unsupported use pattern, which might cause corruption of a geodatabase (preventing function when in a hybrid state and/or proper upgrade). I strongly discourage the use for this purpose.
In fact, I've only had one case where I needed to use Enable Enterprise Geodatabase (and that was on Oracle); at all other times I've used Create Enterprise Geodatabase (after creating the database exactly as I wanted it with createdb, createuser, and psql -- the "Create" tool skips unnecessary steps).