Late reply… Comparing STEP and STL is like comparing a vector to a raster file. A vector file is a more precise representation of geometry. Much like comparing a circle described as a point and a radius vs a circle described as many short line segments. There’s a lengthy thread on this here and loads of other info online:
And the link to What Is The Difference Between STL & STEP Files? (Explained) - Loudspeaker & Acoustic Engineering Design near the top of this thread has incorrect information in the table comparing when to use STEP vs STL files - STEP files are supported by all modern slicers, can be used for 3D printing and are actually better. If you sketch a model in CAD, then rather print using the STEP file than an exported STL file - the print will be better.